How a Nuclear Lab Helped Catch a Serial Killer

It’s the 1990s at a medical center in California, and patients are dying. At first, this doesn’t seem strange — it’s a hospital, and deaths happen. But then rumors start to circulate about a particular health care worker: Difficult or needy patients in his care are ending up dead. The cops get involved, but there’s a huge problem: There’s no hard evidence. Until the so-called “Lab of Last Resort” steps in. Crime Junkie host Ashley Flowers joins us as we speak to analytical chemist Armando Alcaraz, former Detective Sergeant John McKillop and Dr. Ian Musgrave. Find our transcript here: https://bit.ly/ScienceVsSerialKiller In this episode we cover: (00:00) Deaths at a California Hospital (05:20) Meet Efren Saldivar (10:51) A Shocking Confession (15:40) Pavulon and Succinylcholine (21:00) Searching for Suspicious Cases (25:09) The Lab of Last Resort (34:21) Testing the Bodies (39:30) The Story Ends Credits: This episode was produced by Joel Werner and Ekedi Fausther-Keeys, with help from Wendy Zukerman, along with Meryl Horn, Rose Rimler and Michelle Dang. We’re edited by Blythe Terrell. Mix and sound design by Sam Bair. Fact checking by Diane Kelly. Music written by So Wylie, Bobby Lord and Bumi Hidaka. Thanks to Roland Campos, Steve Wampler, Audrey Williams, the audiochuck team, Jasmine Kingston, Connor Sampson, Stupid Old Studios, and Penny Greenhalgh. Special thanks to the LA times staff whose very thorough reporting we used to research this episode. Science Vs is a Spotify Studios Original. Listen for free on Spotify or wherever you get your podcasts. Follow us and tap the bell for episode notifications. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Wendy Zukerman?

  Hi, I'm Wendy Zukerman and you're listening to Science Versus.

• 0:06Wendy Zukerman?

  Today on the show, how a lab that designs nuclear weapons helped catch a serial killer.

• 0:19Wendy Zukerman?

  And if you're gonna do true crime, you better bring in the true crime queen, host of Crime Junkie, Ashley Flowers. Welcome to Science Versus.

• 0:29Speaker 01

  Hello, I'm so excited to be here.

• 0:32Wendy Zukerman?

  So something that a lot of people might not know about you is that you graduated from biomedical science. That was your degree.

• 0:39Speaker 01

  It was.

• 0:40Wendy Zukerman?

  And we are twinsies. We both have this degree.

• 0:42Speaker 01

  I thought I really wanted to be a doctor when I was young and I was, I think, fortunate enough to have to work full-time to put myself through school. And I worked at a hospital for all five years and went to school at night. And I got to work side by side with residents, who you have to be before you're a doctor. And I was like, oh, that's not the life I want.

• 1:05Wendy Zukerman?

  Right.

• 1:06Speaker 01

  I made a bit of a pivot and I finished my degree with actually a focus in research.

• 1:11Wendy Zukerman?

  And so what do you like about science?

• 1:15Speaker 01

  I like facts. And I think so much in life can be so subjective. And what I love about science is it feels like there are real answers and not just opinions. Like there are, sometimes things get to be black and white and that's not very often do you get that.

• 1:32Wendy Zukerman?

  Yes, yes. I think that's one of the reasons I love science too. It's a way to understand the world.

• 1:37Speaker 01

  Yeah.

• 1:37Wendy Zukerman?

  If science is your side piece, I guess, your true love is really mysteries.

• 1:42Speaker 01

  Yes.

• 1:43Wendy Zukerman?

  That I've heard you say that you are obsessed with solving mysteries.

• 1:47Speaker 01

  Obsessed.

• 1:48Wendy Zukerman?

  What is it about a mystery that just grabs you and you cannot let go?

• 1:53Speaker 01

  I think I'm just overall like a very curious person, the more that I've like really drilled into it. And I, I want to, I want the answers to everything. The universe, I want the answers to all the unsolved mysteries. Like, give them to me.

• 2:07Wendy Zukerman?

  Well, today we have a real mystery for you and it's got a whole bunch of science in it. So should we jump in?

• 2:14Speaker 01

  Let's do it.

• 2:19Wendy Zukerman?

  It's two days after Christmas in 1996, and a woman named Selby Asatrian is rushed to Glendale Adventist Medical Center in California.

• 2:31Wendy Zukerman?

  She's 75 years old and is having trouble breathing. One hospital worker told the LA Times about her. He said, "She's a sweet old lady. She got treatment at the hospital, and on December 30th, she's breathing on her own. Things are looking pretty good for her. But then, three and a half hours later, Selby was dead."

• 2:53Wendy Zukerman?

  That same day, Eleonora Schlegel goes into Glendale Adventist. She has some chronic illnesses, a nasty case of pneumonia. On New Year's Eve, her son Larry, he said in a documentary that she was sitting upright and breathing as best as she could. They apparently have this toast and say, "Next year will be better."

• 3:14Speaker 01

  Oh, no.

• 3:15Wendy Zukerman?

  But on January 2nd, Larry sees a message on his answering machine, and it's from the hospital. His mum had died.

• 3:26Speaker 01

  And they're just toasting the day before?

• 3:28Wendy Zukerman?

  Yeah, yeah.

• 3:29Speaker 01

  Oh, my gosh.

• 3:31Wendy Zukerman?

  Similar situation happens again. Jose Alfaro Sr. He was a father. He'd fought in World War II. He arrives at Glendale with severe pneumonia, and two days later is found dead. And at the time, these deaths are sad, of course, but they don't raise any eyebrows because these patients, they were sick, had chronic illnesses. You know, it's a hospital. People die.

• 3:56Speaker 01

  And how close together are all three of these? Like, pretty close?

• 3:59Wendy Zukerman?

  Really close, within days of each other.

• 4:02Speaker 01

  Okay.

• 4:03Wendy Zukerman?

  A few months later, though, rumours have been circulating that the deaths of patients like these didn't happen just because they were sick and elderly, but that these people were killed on purpose by someone who works at the hospital. The rumour is that someone is injecting something into their IV. Ashley, tell me what your face is doing right now.

• 4:26Speaker 01

  Well, I'm just, what do you mean rumors? Like, I feel like this isn't something that should be a rumor if people know that someone's walking around, like, killing people.

• 4:33Wendy Zukerman?

  Yeah, we're gonna get into what these rumors are, who everyone is blaming.

• 4:39Speaker 01

  Okay.

• 4:40Wendy Zukerman?

  What on earth happened here and how the hell a lab that develops nuclear bombs got involved.

• 4:48Speaker 01

  Naturally.

• 4:49Wendy Zukerman?

  Naturally. Are you in?

• 4:51Speaker 01

  I'm in.

• 4:51Wendy Zukerman?

  We're gonna do this just after the break.

• 5:08Wendy Zukerman?

  Welcome back. We've just found out that patients at a hospital in California are dying under, perhaps, suspicious circumstances. Ashley Flowers, host of Crime Junkie, is here with us. Hey, Ashley.

• 5:20Speaker 01

  Hello.

• 5:21Wendy Zukerman?

  So it's now 1997. Whispers are going around that one guy might be killing these patients, and his name is Efren Saldivar. So we talked about him with science journalist Sarah Scholes, who wrote a book about nuclear weapons and stumbled across this case. So Sarah told us that back in Vertigo Hills High School, Efren was a bit of an oddball.

• 5:46Speaker 02

  He worked at a grocery store. He played the oboe. He didn't have a ton of friends, but he was a pretty well-liked kid and was kind of like the leader of the misfits.

• 5:57Wendy Zukerman?

  In the senior wills section of his high school yearbook at Vertigo Hills, he wrote, "I, Efren, of great mind and hunk body, hereby will three-quarters of Vertigo's female population my enduring love and passion."

• 6:15Speaker 01

  Oh.

• 6:16Wendy Zukerman?

  "The right to preserve me in their hearts and souls for the rest of their lives and other times. Eternally yours and mine, Efren Stud at Large."

• 6:29Speaker 01

  Literally, Efren, no one asked. Like, what?

• 6:34Speaker 01

  I mean, it's real oddball energy there.

• 6:37Wendy Zukerman?

  Was he actually of hunk body?

• 6:42Wendy Zukerman?

  You know, was the eighties, um, he was pretty nerdy. A hunk would not be, if I was, if I was making a film, a high school film, he would not be cast in the hunk category. It would more be in sort of the dweeby oddball category.

• 7:01Speaker 01

  I love it. Okay.

• 7:01Wendy Zukerman?

  So Efron makes it through senior year, but ultimately drops out of high school. So he's working at a grocery store and one day.

• 7:10Speaker 02

  His friend came in wearing a medical uniform. He had a friend who was working at a hospital and he, he just really liked this guy's uniform and he was like, I guess I'll do that. I guess I'll get a medical career. I like the clothing.

• 7:25Wendy Zukerman?

  Scrubs?

• 7:26Speaker 02

  Yeah.

• 7:27Speaker 01

  Is he talking about scrubs?

• 7:28Wendy Zukerman?

  He liked the scrubs, which might sound like a weird reason to go into the healthcare profession, but you know, you're 18, keep fit, it's as good as any reason.

• 7:37Speaker 01

  I like cute fit, I like it, but it's pajamas. Like I used to wear scrubs, they're pajamas.

• 7:42Wendy Zukerman?

  I think the person who came in also had a stethoscope, so that might be kind of cool as well.

• 7:48Speaker 01

  Just like radiating power. Yeah, I get it.

• 7:51Wendy Zukerman?

  So Efron enrolls in a respiratory therapy program and respiratory therapists help patients who have trouble breathing. So they give patients drugs, oxygen and manage ventilators, stuff like that.

• 8:02Speaker 02

  Okay.

• 8:03Wendy Zukerman?

  And so when Efron is just 19 years old, in 1989, he gets a job at Glendale Adventist Medical Center.

• 8:11Speaker 01

  I see where this is going.

• 8:12Wendy Zukerman?

  This is the place where the patients at the start of the episode died.

• 8:19Wendy Zukerman?

  So at Glendale Adventist, part of Efron's job was to take care of really sick elderly patients and Efron is put on the graveyard shift. So he starts moonlighting and working at other jobs too during the day, other hospitals. So Efron is working all these jobs. He's a bit overwhelmed and at one point he starts gaining some notoriety at the hospital. So here's Sarah, our journalist again.

• 8:45Speaker 02

  He had a reputation at work for having a, a magic syringe.

• 8:49Speaker 01

  What did they mean by that?

• 8:50Speaker 02

  Not magic in the positive way, but magic in the deadly way.

• 8:57Speaker 02

  His patients died faster than other people's patients.

• 9:03Speaker 01

  That's not magic, that's murder.

• 9:05Speaker 02

  Right?

• 9:05Wendy Zukerman?

  Magic feels like a really weird word to describe it. And this is where, from reporting about this hospital at the time, it seemed like the healthcare workers, particularly the respiratory therapists, had this really, you could call it a dark sense of humour. They just, they played practical jokes on each other.

• 9:27Speaker 01

  So having worked at a hospital, having worked with a ton of people in law enforcement, I have seen this in a place where you see a lot of death or there's like a lot of trauma. Having that like very dark sense of humour tends to be, I've seen a way that a lot of people deal with it. So it's not even super surprising to me to like see that in the hospital setting.

• 9:47Wendy Zukerman?

  Yeah.

• 9:48Speaker 01

  But still.

• 9:49Wendy Zukerman?

  And then sort of other things start happening that make it harder to pass off as a joke. So here's Sarah.

• 9:57Speaker 02

  Someone had seen him putting something in an IV line that they thought shouldn't be there.

• 10:04Wendy Zukerman?

  A coworker also says he sees an empty syringe and a bunch of drugs in Efrain's locker. Drugs like morphine and this medication called succinylcholine, which is going to become important later.

• 10:16Speaker 02

  Okay.

• 10:17Wendy Zukerman?

  And so in April of 1997, a coworker ends up reporting Efrain to a supervisor. But the supervisor doesn't know about the drugs in the locker. So they really don't have that much to go on. It's just kind of rumour in a place where there's a lot of rumours and jokes going around. But still, they look into the hospital records to see if Efrain's patients are dying more often than other patients.

• 10:41Speaker 02

  Hmm.

• 10:42Wendy Zukerman?

  And...

• 10:44Speaker 02

  Didn't find anything because his patients weren't actually dying at a higher rate than anyone else's?

• 10:50Wendy Zukerman?

  Oh. Yeah, so they didn't find anything unusual here. They let it go, Efrain keeps working. And it's not until almost a year later, in February 1998, that the hospital receives another tip.

• 11:04Speaker 02

  From someone who says that there is a respiratory therapist who the quote is "helped a patient die fast."

• 11:12Speaker 01

  And is this like a euthanasia situation? Or what is that like? What do they mean?

• 11:17Wendy Zukerman?

  The guy on the phone ends up being a pretty dodgy guy with a criminal record and seems to be implying that if he gets an extra $50,000, he'll give more information.

• 11:30Speaker 01

  Wow.

• 11:31Wendy Zukerman?

  He's basically extorting the hospital.

• 11:32Speaker 01

  Yeah.

• 11:33Wendy Zukerman?

  And so this time, the hospital calls in the Glendale Police Department. And by the way, we did reach out to the hospital to ask them about parts of this story.

• 11:44Speaker 01

  And let me guess, they didn't want to talk?

• 11:45Wendy Zukerman?

  Yeah.

• 11:47Speaker 01

  They said, "Let me finish that for you."

• 11:50Wendy Zukerman?

  Thank you. Yes, all questions should be directed at Glendale Police Department.

• 11:56Wendy Zukerman?

  So, enter Detective Sergeant John McKillop from the Glendale Police Department. He is put onto this case and John and his team start poking around. And John told us that he is actually not buying this idea that Efrain is a killer.

• 12:14Speaker 03

  I was a skeptic because it just seemed odd. The whole thing seemed odd.

• 12:19Wendy Zukerman?

  What was so odd about it?

• 12:20Speaker 03

  Well, I mean, to be honest, you're talking about someone trying to extort money out of the hospital to give information versus a major serial killer. I just thought it was a bunch of bull, so to speak.

• 12:39Wendy Zukerman?

  How are you feeling at this point, Ash? What's your spidey senses telling you?

• 12:43Speaker 01

  I mean, I under, well, I understand what he's saying. And it's funny, like, I feel like the way that I'm at least hearing this is that the hospital really brings in the police because of the extortion, not because of the threat of somebody actually killing their patients.

• 12:56Wendy Zukerman?

  Yeah, that's, that's John's memory of it as well. Yep.

• 12:59Speaker 01

  Yeah, yeah, yeah, yeah, yeah. Got you, got you, got you, John. So I understand why he would just kind of come in with that thought of like, well, this can't be true. It's just some guy, he wants $50,000 to out a serial killer. Like, there's no way.

• 13:13Speaker 04

  I would probably think the same thing too.

• 13:15Wendy Zukerman?

  Yeah, so but still, to sort everything out, on March 11th, 1998, John's partner, Detective William Curry, calls Efren into the station just to ask him some questions. But John actually had something else to do that day.

• 13:30Speaker 03

  Will was gonna bring Efren in to interview him. I'm like, I'm gonna go play hockey. So I went to my hockey game.

• 13:36Speaker 04

  You were so sure that like, this is silly.

• 13:39Speaker 03

  Yeah, exactly.

• 13:41Speaker 01

  I love it.

• 13:42Wendy Zukerman?

  Right.

• 13:42Speaker 01

  It's like, no need.

• 13:43Speaker 04

  I've got hockey.

• 13:44Speaker 01

  You take care of this.

• 13:45Wendy Zukerman?

  But it turns out, this was not silly. When the cops start questioning Efren, he confesses to killing dozens of patients.

• 13:55Speaker 01

  He like, all they had to do was ask some follow up questions and the dude just folds?

• 13:59Wendy Zukerman?

  Pretty quickly, he says he killed forty to fifty people.

• 14:04Speaker 01

  Oh!

• 14:05Wendy Zukerman?

  Yeah.

• 14:07Speaker 01

  Over like, what span of time?

• 14:09Wendy Zukerman?

  It's pretty vague at this point. He's it's very, the cops just found it very strange, particularly given this attitude of, I'm gonna go play hockey, sure, bring him in. They want him to do a polygraph. The way that the cops remember it is just, all of a sudden, he starts talking and they were in the room going, wha- wha- oh, uh, uh.

• 14:27Speaker 01

  Someone get a pen, like, write this down.

• 14:29Wendy Zukerman?

  Exactly, exactly. And so John is playing hockey.

• 14:32Speaker 03

  I mean, they literally pulled me off the hockey rink to tell me, hey, your partner's on the phone, there's something going on, you need to go. And when I picked up the phone, Will says, this guy's confessing, he's rolling over, you need to get in here right now. You know, now we're talking about murders.

• 14:47Wendy Zukerman?

  Oh my god. So not only did he say that he killed patients, but he also told the cops how he did it. Like, sometimes he would kill them with these drugs. He said he either used a drug called Pavilon or one called succinylcholine.

• 15:05Speaker 01

  Which is what they found in his locker. Wow.

• 15:07Wendy Zukerman?

  Exactly.

• 15:08Speaker 01

  Does he say why?

• 15:10Wendy Zukerman?

  At the time, he said that he did it to ease the suffering of these patients.

• 15:16Speaker 01

  But we had our homegirl over here who's like cheersing to a brand new year.

• 15:20Wendy Zukerman?

  Yes, yes. It doesn't, it doesn't really make sense.

• 15:25Speaker 01

  Okay.

• 15:25Wendy Zukerman?

  He sort of fashions himself as a little bit of an angel of death type character in that room, that he didn't like seeing the patients suffering, says things like that.

• 15:36Speaker 01

  Okay.

• 15:39Wendy Zukerman?

  So we wanted to know a little bit more about what these drugs do in the body and why they're used by healthcare workers. So we talked about this with Dr Ian Musgrave and he's a molecular pharmacologist at the University of Adelaide in Australia. He told us that Pavillon and succinylcholine, they interfere with how a particular neurotransmitter works in our body and ultimately they can paralyze your muscles.

• 16:04Speaker 05

  They stop the nerve signaling, so your muscles just stop working. Now you may be saying, okay, why would you want to paralyze respiratory muscles?

• 16:13Wendy Zukerman?

  That is, if you don't want to kill someone, why are we using these drugs in hospitals? And well, these drugs are sometimes given to patients before surgery and it helps doctors to intubate them, you know, put the tube down their throats. It can stop you from gagging. Or if you wake up during, let's say, surgery, it would keep you from moving around, so a scalpel doesn't slip. But because these drugs paralyze the muscles that allow you to breathe, if you're using them in a medical setting, you have to give someone a breathing tube or a respirator. So you're giving them oxygen artificially.

• 16:49Speaker 05

  Of course, if you give a paralyzing dose of these drugs without putting in a breathing tube and without artificially respiring them, guess what happens?

• 16:59Speaker 01

  Everything shuts down.

• 17:00Wendy Zukerman?

  They die.

• 17:02Speaker 05

  They suffocate because they can't breathe.

• 17:04Wendy Zukerman?

  What would it be like to die like that?

• 17:07Speaker 05

  Incredibly horrible. You're paralyzed and you can't move and you can't react and you're suffocating to death.

• 17:13Wendy Zukerman?

  If some of his victims weren't unconscious, they would have felt it.

• 17:19Speaker 05

  They would have definitely felt it.

• 17:24Speaker 01

  Oh, just like silent suffering.

• 17:28Wendy Zukerman?

  Yeah, that's right. Because Ian, we talked about it and he said it would be almost like drowning because you're not anesthetized necessarily. So these drugs don't conk you out or, you know, put you to sleep. So you just can't breathe.

• 17:45Speaker 01

  And you can't even like move or scream. Oh my gosh, I can't imagine.

• 17:48Wendy Zukerman?

  Awful, awful. Now, it is worth saying that in Efferon's confession, according to the cops, he said that he would only do this to patients who are unconscious.

• 17:57Speaker 01

  I don't, like, there's no way. All 40 of them?

• 18:00Wendy Zukerman?

  Yeah, I don't know how we can know that for sure exactly. So the cops hold Efren Saldivar on suspicion of murder. But even though he'd given this detailed confession, admitted to killing dozens of people, in the US, that's not enough to go on because of this rule that's called corpus delecti. Yeah, so tell us about it, body of the crime, tell us what it is.

• 18:22Speaker 01

  So the corpus delecti, you can't convict someone just based on a confession. Their confession has to actually match some kind of physical evidence. We're basically like, if you took the confession away, you have to still be able to prove that they did it by some other means, whether that's physical evidence, circumstantial evidence, other witnesses. But you should not be able to convict someone just by them saying, I did this thing.

• 18:47Wendy Zukerman?

  Yeah, and in this case, all they have is a confession. They don't have any physical evidence because these patients really just could have died because they were sick.

• 18:55Speaker 01

  Yeah, okay.

• 18:57Wendy Zukerman?

  So John, the cops, hold him for a couple of days while they're doing some detective work. But in 48 hours, what's he going to come up with? And so they have to let him go. And when he gets out, Efren goes on national television and says that he lied about the confession. And Sarah, our journalist, told us that Efren basically says.

• 19:19Speaker 02

  I didn't do it. I was depressed and suicidal and thought this was a way out. And the detective pressured me, and so I don't confess anymore.

• 19:29Wendy Zukerman?

  A way out of what? A way out of life. He sort of gave this idea that he was really depressed and basically suicidal and thought that if he confessed to these killings, then maybe he would be given the death penalty and then that would be his way out.

• 19:47Speaker 01

  Okay, but then he changed his mind, he says.

• 19:50Wendy Zukerman?

  I guess so, I guess so. He also said at the time that he was taking Valium and other sedatives and barely remembered what he said to the cops. And even a hospital spokesman around that time said, quote, "We don't know if anything happened," end quote.

• 20:08Speaker 01

  Mm-hmm.

• 20:08Wendy Zukerman?

  Mm-hmm.

• 20:09Speaker 01

  Mm-hmm.

• 20:09Wendy Zukerman?

  Did he get?

• 20:11Speaker 01

  You know, in a room and pressured, like that's an easy thing to say. Like, do you also say the thing that's been weighing on you? And then all of a sudden, when like the gravity of what that means and like what the consequences are, when the gravity of that sets in, the story changes? Like, oh, maybe I, oh, gosh, I didn't know what I was like saying.

• 20:29Wendy Zukerman?

  Yeah. But meanwhile, the medical board responsible for respiratory therapists suspends Efrain's license to practice. So he's no longer working at the hospital. And the cops, cops like John, they're not totally buying that his confession was a lie because it was just so specific, the drugs he used. You know, yeah, how, exactly how he did it. It felt like a weird thing to just say. So the cops stay on the case and actually create a task force to find out what is going on here. And they start going through every patient that died under Efrain's watch.

• 21:13Wendy Zukerman?

  And they're looking for suspicious cases. And this is a huge task. It meant wading through more than a thousand complicated medical records.

• 21:23Speaker 03

  Oh, it was completely crazy. I mean, we're cops, we're not doctors. So we had to learn how to read medical charts and do all that stuff, quickly trying to become experts at something that none of us had expertise in.

• 21:35Wendy Zukerman?

  But they talk to the doctors and they learn fast. And they're looking for patients who weren't given Pavelon or succinylcholine legitimately at the time of their death, so they didn't need it for surgery. They start looking for patients as well, who at the time of their death, had this particular pattern in their breathing and heart rate moments before they died that might suggest they were given Pavelon or succinylcholine. They're also on the hunt for situations like salbiocatryans and the other patients we talked about at the start of the show, where they're doing better and then suddenly they die for no clear reason.

• 22:20Speaker 01

  Mm hmm, like nosedive, yeah.

• 22:22Wendy Zukerman?

  And so after months of trawling through these records, they come up with 20 people whose deaths at the hospital were highly suspicious.

• 22:32Wendy Zukerman?

  And so now the plan is to exhume the bodies from a cemetery and search for the drugs that Efrain had said he used to kill the patients.

• 22:41Speaker 01

  And are they the kind of thing that would last for a while? Like in the system, like would you still see them?

• 22:48Wendy Zukerman?

  Ashley, that is the question. Because the cops start asking around and they realize that we do not have a good test to find these drugs in this situation.

• 23:01Speaker 01

  Oh.

• 23:02Wendy Zukerman?

  Basically, you can't pull out some easy peasy test off our forensic science shelf that would detect what's expected to be pretty low levels of pavlov or succinylcholine in a decomposing human body. So bottom line, even if they exhumed those bodies from those graveyards, there's no reliable test to find these drugs inside them.

• 23:26Speaker 01

  They've got nothing. So now what?

• 23:29Wendy Zukerman?

  The story can't end here, obviously. Obviously. They get a tip that there is this place that just might be able to help them. It's a lab that some call the lab of last resort.

• 23:44Speaker 01

  What a name.

• 23:45Wendy Zukerman?

  It's where we're at in this story, right?

• 23:48Speaker 01

  Yeah, true.

• 23:50Wendy Zukerman?

  This lab is called the Lawrence Livermore National Laboratory. It's this huge sprawling facility in California that was created in the early days of the Cold War and does some truly bonkers stuff. So they design nuclear warheads. They have one of the world's most powerful lasers. And they also have this forensic science center that can trace tiny amounts of chemicals.

• 24:14Speaker 01

  Why? What are they doing at this lab?

• 24:16Wendy Zukerman?

  So they use it to find chemical weapons, evidence of chemical weapons in an environment.

• 24:22Speaker 01

  Oh.

• 24:22Wendy Zukerman?

  And also alleged murderers. And here's how John describes this lab.

• 24:30Speaker 03

  I don't know if you know about this place, but it's like, I mean, they weigh you when you go in to make sure your weight is consistent with what's on your ID and, you know, fingerprint you. And it's like a high, really super high level, high security kind of village.

• 24:49Wendy Zukerman?

  After the break, we'll get inside that high-security village, the lab of last resort.

• 24:55Speaker 01

  Let's do it.

• 24:56Wendy Zukerman?

  Is coming up.

• 25:12Wendy Zukerman?

  Welcome back. Today on the show, I'm here with Ashley Flowers, host of Crime Junkie, and we are cracking the case of Efren Saldivar, a healthcare worker who's suspected of killing dozens of patients. Wide open.

• 25:24Speaker 01

  Let's do it.

• 25:25Wendy Zukerman?

  So we're now heading to the Forensic Science Centre at Lawrence Livermore National Laboratory in California.

• 25:31Speaker 01

  The lab of last resort.

• 25:33Wendy Zukerman?

  And it's now up to some serious nerds to try to detect the tiny amounts of drugs in bodies that have been buried for years.

• 25:42Speaker 01

  Mm-hmm.

• 25:43Wendy Zukerman?

  Armando Alcaraz is an analytical chemist who works at Lawrence Livermore, and he was on the team who had to now create this test. And when he heard about what he had to do, he was like...

• 25:56Speaker 06

  Oh, my God. Where are we gonna find this stuff? And I was a big skeptical. I thought it was still gonna be enough contamination, and at such low levels, that we weren't gonna be able to see it. And we would then have to sort of pull that needle, you know, out of a haystack.

• 26:13Wendy Zukerman?

  So here's what they have to do. Let me describe the needle and the haystack. So needle is the drugs. The haystack are the loads of other chemicals that would be in these decomposing bodies. Armando told us that some of the patients were smokers, so tobacco would have been contaminating the tissue, so would any embalming fluid used in the burying process. Dirty water would have been seeping into the coffins by now, leaching in all of these chemicals from the soil surrounding it. And it meant that if you were to look in liquid in their bladder.

• 26:50Speaker 06

  Yeah, at that point, you don't know whether it was actually real urine or whether water seepage had gotten into that coffin and there was moisture in it and that's what you're analyzing.

• 27:00Wendy Zukerman?

  Oh, right. You don't even know if it's like body fluid or outside fluid or, ugh. Exactly. So they get to work and they quickly realize that one of the drugs that Efrain had said he used to kill patients, succinylcholine, that is basically a lost cause. It's just too hard to identify it in a human body after all this time.

• 27:21Speaker 06

  And the reason is it breaks down real fast. And when it breaks down into the metabolites, those metabolites can be found in the human body anyway. So how could you go into a court of law and say, well, here we found these metabolites? Well, the defense lawyers are going to go, well, and what does that mean? They're normally found in a human body anyway. But with Pavelon, there's no reason why a person should have that drug in their system unless they had a procedure or somebody injected them with it.

• 27:51Wendy Zukerman?

  So they zoom in and try to create a test to identify Pavelon. And because they don't want to be doing this work in human bodies, they start working with something that's pretty close to a human body. Pig pigs. Do it. Yes, yes. So Armando and his colleague get pig livers and they add a tiny bit of Pavelon.

• 28:14Speaker 06

  Spike it, you know, put the chemical in it and then just allow it to putrefy. And then you take it out and homogenize it. You basically put it in a blender and make milkshake out of it.

• 28:25Wendy Zukerman?

  Your face in this moment. I know, it's like the milkshake pig liver. Yeah, you can really feel it in your throat, can't you? Mm hmm. Uh, things are about to get a little bit grosser. So because they would take this pig liver Pavelon milkshake.

• 28:43Wendy Zukerman?

  And in some cases, let it sit and decay for months, making it more like what these bodies that have been decaying would be like. At this point, Armando and particularly his boss, Brian Andreessen, are up to their elbows in decomposing pig livers. Word on the street is that the lab did smell kind of gross. What did it smell like?

• 29:07Speaker 06

  There's these two notorious chemicals, putrescine and cadaverine. So just, just the names themselves kind of give you an indication of what it smells like.

• 29:16Wendy Zukerman?

  Cadaverine? Is that what you said?

• 29:18Speaker 06

  Cadaverine and putrescine.

• 29:20Speaker 01

  It had to have smelled so awful. I just went into my first morgue for the first time recently and, and there weren't even like, that was bad. I have no clue what this place would smell like.

• 29:31Wendy Zukerman?

  So, so decomposing bodies, whether it's pigs or humans or whatever, they emit these chemicals. And the two that he talked about, cadaverine and putrescine, they give off that particular smell of death, that smell that you described. And here's how Armando described it.

• 29:50Speaker 06

  It's everything awful you could think of. That's rotting. That's what it smells like. And so I have to tell you this story because I spoke to Brian and we would be working late at night, you know, trying to get these samples through. And he would be, you know, blending these tissues up with a blender. And even though we were doing all this in the chemical hoods, you could still smell that stuff. And it would penetrate your clothes. It would get into your clothes. And so it would already be maybe nine thirty at night, it was late, you know, and he said, I'm, I'm gonna go and I'd leave too. He'd go to the grocery store to go buy some stuff to eat. And so he would be standing in line and people would start to just move away from him.

• 30:32Speaker 06

  Because he had sort of was, you know, that smell of death was just in his clothes and in his hair and everything.

• 30:40Speaker 01

  It stays on you. I've talked to detectives who have said that there are scenes that they come home from and they have to just like burn their clothes or throw away their clothes because no amount of washing will get it out. There is just like a level that is beyond anything I think most people know. Yeah, bad.

• 30:54Wendy Zukerman?

  So while covered with this smell of death, they take the, we're going to go back to the decaying pig milkshakes that have been spiked with pavillon. And they pass them through this particular contraption that's called a solid phase extraction polymer.

• 31:14Wendy Zukerman?

  It looks a bit like a plastic syringe and it has a kind of filter in it, or what's called a cartridge. And inside it, they're basically trying to separate pavillon from all the other crap that is in these tissue samples. But what you have to know is that there's different cartridges out there that are used to isolate different chemicals. I had never thought about how one would isolate chemicals from a human body.

• 31:38Speaker 01

  Mm hmm.

• 31:39Wendy Zukerman?

  Not what I've spent my brain power on.

• 31:41Speaker 01

  No.

• 31:42Wendy Zukerman?

  And so basically they're pushing all tiny bits of samples through these little syringes. And what the game is to find the exact right cartridge that's going to trap pavillon, but leave out

• 31:56Speaker 01

  Everything else.

• 31:56Wendy Zukerman?

  Everything else, or as much as possible of everything else. And so Armando's colleague has been working on finding the right cartridge. Armando's focusing on another piece of this puzzle. It's really tough. Just passing this milkshake through these filters could take days, depending on how decayed the tissue is or how much mucus is in it. May turns into June, they're pulling 16 hour days. It's just late night after late night.

• 32:26Speaker 06

  They had that task force that was just sitting there waiting for the results so they could move forward. So that was putting a lot of pressure on us and that's why we were working late.

• 32:37Wendy Zukerman?

  They're not finding what they need. It's depressing. Nothing is working.

• 32:42Speaker 06

  No, but what the heck's going wrong? And so the instrument would start leaking on me, the solvents, and I'd be frustrated and just like, oh, pulling my hair out.

• 32:51Wendy Zukerman?

  But then one day, Brian is testing this cartridge that was designed to detect the residue of chemical weapons. And from across the room, Armando hears his colleague saying something.

• 33:03Speaker 06

  He goes, I think we're there. It was solid. Actually, what the cartridge did was it acted like a magnet, where it would just collect the drug, or things similar to the drug, and sort of it gripped on to it. And then it allowed us to then wash off all of like the tobacco products and other biomaterials that were in the tissue, but the drug stayed attached.

• 33:29Wendy Zukerman?

  Wow.

• 33:30Speaker 06

  But yeah, that was amazing. That was a magic cartridge.

• 33:34Wendy Zukerman?

  Holy crap. That is incredible. Isn't it? They found the magic cartridge. So Armando would now extract all the chemicals in the cartridge and then using a bunch of tools like mass spectrometry. Oh my god. This is why we call it mass specs, because there's so many Rs in that word. Using tools like mass spectrometry, which separates chemicals based on their weight, and then try to identify pavillon in that sample. And here, Armando catches a break because it turns out that pavillon creates this really unique signature, which meant, yes, they can identify this drug.

• 34:14Wendy Zukerman?

  And so now, it's time to see if what works in pig livers works in human bodies. So in the spring of 1999, the cops start driving out to the graveyards and bodies start getting exhumed. And John said, even for him, this pulling out bodies from the ground, this was, this was rough.

• 34:38Speaker 03

  I've seen a lot of dead bodies, but when you exhume a body, it's unnatural. You're pulling the casket out of the ground, you're cracking open the casket, and you don't know what you're gonna find. One time we opened a casket, and the maggots inside the casket were jumping out, like, I can remember them landing on my protective gear on my chest.

• 35:06Speaker 01

  Oh, that is rough. That's like not part of the job description. Oh.

• 35:13Wendy Zukerman?

  So the caskets get opened, bodies removed, tissue samples are taken out and then sent to the lab of last resort. Finally, after all this time, Armando and his colleagues start testing their very first patient. And, you know, at this point, if they find Pavelon in these bodies, it really does mean, you know, there was no reason for Pavelon to be in their system unless Afrin had put it in there. So they start testing patients.

• 35:43Speaker 06

  We didn't see anything. I mean, there was no signal. Then the second set of samples for the second patient, and there was nothing there. And then, you know, the third one, nothing there. And then I'm thinking, oh, God, what's going on? Is there just nothing in some of these tissues? You start to doubt whether you're going to see anything.

• 36:05Wendy Zukerman?

  And then they test the fourth patient.

• 36:09Speaker 06

  And I was like, I got something here. There's, it's there. And so I ran over to Brian, I got, I pretty much ran over there saying, you gotta look at this. We got a hit on this. It's confirmed. It's there. It was that, yes, we did it. So then we were, we were on a roll and we started looking at various tissues from that individual. And sure enough, we were getting positives, you know, on the kidney, on the bladder tissue, on the brain. So all of these, that one patient was hot.

• 36:42Wendy Zukerman?

  Wow. Yeah. They test another body, they don't find it, but then they get another hit and another hit. And they tell the cops, you know, these Pavelon, we are finding it. And John remembers how he felt.

• 36:56Speaker 06

  So finding the drug was a huge moment. We kind of erupted in clapping and like cheering type of thing. And then finding the drug in multiple patients, that was the, then we knew, we knew we had it.

• 37:13Speaker 01

  They did it. They did it. So do they have to go exhume every single patient that he's ever come in contact with? Or like, where do they go from there?

• 37:22Wendy Zukerman?

  Yeah, so they picked out the 20 patients that were most suspicious because they couldn't exhume a thousand bodies. So these are the suspicious cases.

• 37:32Speaker 01

  And do they think that the others truly didn't have it in their system? Like, they would have detected that? Or they're unsure about the other ones?

• 37:42Wendy Zukerman?

  I think we don't know. They could have been killed with succinylcholine instead. Or it could have been that the pavillon wasn't at too low levels to detect. Or it could be that maybe the rest of the patients actually weren't killed by Efren. We don't know. That's the thing, when you don't find the chemical, you just don't know what the answer is. But finding the chemical showed that at least with six patients, there was this drug in there. Because that's how many patients, that's how many bodies that they found pavillon in. In the end, it was six, including Chris Alfaro, who fought in World War II, Salbi Asatrian, and Eleanor Schlegel, who toasted to the New Year with her son.

• 38:28Wendy Zukerman?

  And still, after this test, the cops actually aren't ready to arrest Efren just yet because this was happening just a few years after the OJ Simpson trial. And that case kind of fell on its face because the cops messed up and mishandled evidence. So Armando and his colleagues not only test the bodies for pavillon, but then all kinds of stuff around the bodies. Because there was this suggestion that maybe pavillon would be in the soil or would have been in the crypt water or the embalming fluid and then made its way into the bodies. And so they test that stuff. Everything's looking fine. You know, when Ian Musgrave, who was our pharmacologist, read details about their work,

• 39:10Wendy Zukerman?

  he said, and I have never heard an academic describe a paper like this, but he said it was like seeing an experienced figure skater. Every move is smooth and beautiful.

• 39:26Speaker 01

  I love that. This one can appreciate the art.

• 39:29Wendy Zukerman?

  Yeah.

• 39:29Speaker 01

  Yes.

• 39:30Wendy Zukerman?

  And so in January 2001, this is three years after Efrain's first confession. The cops arrest him on his way to work at a construction site. John brings him in for questioning. He tells Efrain all the evidence that they have, that Pavillon was found in six bodies.

• 39:49Speaker 03

  Well, we kept asking them, how many do you think you killed?

• 39:56Speaker 03

  Oh, he's very soft spoken and you could barely hear him. I think some, it was sometimes he was like writing stuff down and passing notes to us in the, in the interview.

• 40:08Wendy Zukerman?

  And as John remembers it, Efrain confesses to killing the patients. And at first he won't say how many he killed. And instead, he tells John what it takes to kill patients using Pavillon. And he says, with just one vial, you like, you can kill a lot of people.

• 40:29Speaker 03

  Well, I can kill 10 people per vial and I probably had used 10 or 20 vials over the years. And so it was probably 100 to 200.

• 40:40Speaker 01

  What?

• 40:41Wendy Zukerman?

  Yeah.

• 40:42Speaker 01

  Oh, my gosh.

• 40:43Wendy Zukerman?

  Your mouth fell agape when you heard these numbers. Tell me what you're thinking.

• 40:49Speaker 01

  That's so prolific. Is, and it's, how do you even, has he kept a record of who these people were? How do you even go back and try and find out who they were?

• 40:59Wendy Zukerman?

  No, he didn't remember the patients. I mean, he even said, uh, that he like lost count at 60 patients.

• 41:08Speaker 01

  And it's, and he can't still be saying like, he was like trying to save them from their own suffering, right?

• 41:14Wendy Zukerman?

  So as for the question of why he did it, John actually got, when I asked him, the cop, you know, what do people get wrong when they report this story? And he, he got quite passionate and he just said, you know, this case has been reported as an angel of death case that Efrain was trying to reduce their suffering. But for this case, I mean, John says that they were specifically looking for victims who were getting better. You know, like you said, who were toasting New Year's.

• 41:41Speaker 01

  Yeah.

• 41:41Wendy Zukerman?

  Who wanted to live. And in that confession room, Efrain told John that there was a completely different reason for doing what he did.

• 41:50Speaker 03

  He would get irritated that he would have to go tend to a patient. So bottom line with him was every patients were irritants. They disrupted his day. You know, patients in hospital are very needy and clicking that button a lot. And so he confessed to killing because of workload.

• 42:08Speaker 01

  Sir, what did you think you were signing up for?

• 42:10Wendy Zukerman?

  Yeah.

• 42:10Speaker 01

  You could have worn scrubs at home. What the [bleep]? I don't know if I want to swear on this, but what the [bleep]?

• 42:15Wendy Zukerman?

  Yeah.

• 42:16Speaker 01

  Yeah. What?

• 42:18Wendy Zukerman?

  Yeah. He told the police that, quote, "It was not something that gave me joy." And then he said, quote, "Only when I was only at my wits' end on the staffing, I'd look at the board, who we got to get rid of."

• 42:33Speaker 01

  What?

• 42:35Wendy Zukerman?

  So callous. We talked to Sarah, our, our science journalist, about the victims.

• 42:41Speaker 02

  There was one woman who actually survived the attempt because he didn't give her enough and she pressed the call button too much and annoyed him. And so he dosed her.

• 42:53Speaker 01

  There's like, that doesn't even like, that doesn't even like register. I just, like, can someone be that cold? It almost would make more sense if he, you know, did like get some kind of like joy or something from the actual killing. Like, that almost makes more sense to me than just being like, well, too many people today, so like, which one's going to lose their life so we can like have a manageable schedule?

• 43:20Wendy Zukerman?

  Yeah. Efrain took a plea deal and was eventually convicted of killing the six patients that Armando and his colleagues found Pavillon in. Efrain was sentenced to six consecutive life terms without the possibility of parole for the murder counts and 15 years to life for the attempted murder of Jean Coyle, who was the woman who survived. And there is this extra weird twist to this story, Ashley, because if Efrain had gone to trial instead of taking a plea deal, he might have been faced with the death penalty. And at that time, if he got the death penalty,

• 43:59Speaker 01

  Oh!

• 44:00Wendy Zukerman?

  Do you want to guess?

• 44:01Speaker 01

  They would have used the same drug.

• 44:02Wendy Zukerman?

  Yes. One of the drugs that they would have used to kill him was Pavillon.

• 44:08Speaker 01

  Wow.

• 44:16Wendy Zukerman?

  So Ashley, that's the case of how some nerds used some smooth and beautiful moves to catch a killer.

• 44:23Speaker 01

  I love it.

• 44:24Wendy Zukerman?

  Science saved the day?

• 44:26Speaker 01

  Yeah, I mean, I think science is always saving the day, right? Like, in the world that we live in, and I love this because I love the idea that, oh, we didn't know what, the test didn't exist. And so instead of being like, oh, sorry, there's something to do. That doesn't mean it can't happen. Science is like happening all the time around us. If we like make it happen, just because a test doesn't exist today doesn't mean it won't tomorrow.

• 44:45Wendy Zukerman?

  Yeah, exactly. Well, thank you so much for joining the show, Ashley.

• 44:51Speaker 01

  Thank you for having me.

• 44:57Wendy Zukerman?

  If you want to know more about this case, then go check out our transcript. So in the show notes for this episode, there's a link to our transcript and it's fully cited. So there's links to Armando's amazing work that looks like a figure skater and also links to some amazing reporting that was done by staff at the LA Times, who we used to help make this episode. Also, Sarah Scholl's book is called Countdown: The Blinding Future of Nuclear Weapons. And this story didn't make the cut, so it's called Countdown: The Blinding Future of Nuclear Weapons.

• 45:40Wendy Zukerman?

  This episode was produced by Katie Foster Keys and Joel Werner, with help from me, Wendy Zukerman, along with Merrill Horn, Rose Rimler and Michelle Dang. We're edited by Blythe Terrell. Mix and sound design by Sam Bear. Fact checking by Diane Kelly. Music written by So Wiley, Bobby Lord and Boomi Hidaka. A special thanks to Roland Campos, Steve Wampler, Audrey Williams, the audio check team, Jasmine Kingston, Connor Sampson, Stupid Old Studios and Penny Greenhalgh. Science vs. is a Spotify Studios original. Listen to us for free on Spotify or wherever you get your podcasts. And if you are listening on Spotify, follow us and tap the bell icon so you'll get notifications when new episodes come out.

• 46:21Wendy Zukerman?

  Also, if you do like the show, we would love it if you would give us a five star review because it really helps new listeners find the show. I'm Wendy Zukerman. Back to you next time.