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Her name was Isis Charm Vas and at 6 months old she was a slight child – fifth percentile in height and weight.
When the ambulance sped her to Northwest Texas Hospital in Amarillo on a Saturday morning in October 2000, doctors and nurses feared that someone had done something awful to her.
A constellation of bruises stretched across her pale skin. CT scans showed blood pooling on her brain and swelling. Blood was found in her vagina. The damage was so severe that her body's vital organs were shutting down.
Less than 24 hours later, Isis died.
An autopsy bolstered the initial suspicions that she'd been abused. Joni McClain, a forensic pathologist, ruled Isis' death a homicide and said the baby had been sexually violated. McClain would later describe it as a "classic" case of blunt force trauma, the type of damage often done by a beating.
The police investigation that followed was constructed almost entirely from medical evidence. In the end, prosecutors indicted one of the child's babysitters: Ernie Lopez.
Today, Lopez is serving a 60-year prison term for sexual assault and is still facing capital murder charges.
But in the years since Lopez was sent to the penitentiary, a growing body of evidence has emerged suggesting that McClain and the hospital staffers were wrong about what happened to Isis — and that her death was not the result of a criminal attack.
If Lopez is ultimately exonerated, his case will not be unique. An investigation by NPR, ProPublica and PBS Frontline has found that medical examiners and coroners have repeatedly mishandled cases of infant and child deaths, helping to put innocent people behind bars.
We analyzed nearly two dozen cases in the United States and Canada in which people have been accused of killing children based on flawed or biased work by forensic pathologists, and then later cleared.
Some spent years in prison before courts overturned their convictions. In 2004, San Diego prosecutors moved to dismiss charges against a man who'd been imprisoned for two decades for murdering his girlfriend's son.
Others were freed more swiftly but endured hardships nonetheless. An El Paso, Texas, jury acquitted a woman of killing her child in 2010, but after spending 22 months in the county jail, she still had to wage a legal battle to regain custody of her other children.
The questionable prosecutions identified in our joint investigation had common elements:
Often, authorities had little to go on other than autopsy findings. Many of the doctors who conducted post-mortem examinations failed to consult specialists in childhood injuries or ailments, or to thoroughly review medical records that could have affected their conclusions. In several cases, forensic pathologists worked so closely with authorities, they effectively became agents of law enforcement, rather than objective arbiters of scientific evidence.
Some experts in the field say worries about mistakes in child death cases are overstated. "The vast majority of forensic pathologists recognize a child abuse case when they see it, and it's not because they want to persecute people," said Mary Case, chief medical examiner for four Missouri counties including St. Louis County.
But others say the criminal justice system has yet to confront the full scope of the problem, and that, as a result, more innocent people may be serving time for crimes they didn't commit. "I think it's time to look at these cases again," said Michael Laposata, chief pathologist at Vanderbilt University Medical Center, adding that this could "result in the liberation of a number of falsely accused people."
Lopez, 40, a soft-spoken man with a slight twang, still can't quite believe he may spend the rest of his life locked up for something he says he didn't do: harming the infant he nicknamed "Little Bird."
"Sometimes I wake up and I look at my cell and man, it just hits me: You know, I'm in prison," he said in an interview. "I never thought I would be in prison, never in a hundred years."
The 9-1-1 Call
At 10:55 a.m. on Oct. 28, 2000, Ernie Lopez grabbed the cordless phone at his house and dialed 9-1-1.
"What's going on? What's going on?" asked the operator.
"OK, my ... We're babysitting this little baby girl for Dr. Vas," said Lopez, according to a recording and transcript of the call. A spider, he explained, had bitten Isis a week earlier, "and she's been acting funny ever since."
Lopez and his wife, DeAnn, regularly babysat Isis and her two older siblings, both toddlers. The children's mother, Veronica Vas, was a physician at a nearby hospital, and on that morning she was on her way to Detroit for the weekend.
Lopez, a burly, gregarious man who worked as a mechanic, was looking after the children while DeAnn went shopping for a dress for the annual Lopez family Christmas photo, scheduled to be taken that afternoon. He had been watching the Vas children for 40 minutes when he called for an ambulance.
On the phone, Lopez described his efforts to revive Isis. "I tried to slap her on the bottom and slap her on the face and she won't wake up. She won't do nothing." Blood spilled from her mouth. "She was bit about 14 times. ... She's got all these bruises around her neck and on her face where she was bitten." After the ambulance arrived at his modest one-story home, Lopez rode with Isis to the emergency room.
Police detectives, alerted by hospital staffers, quickly showed up at the hospital to question Lopez. He wept as he spoke to the officers.
By the time Isis died a day later, police had arrested Lopez.
The body of the baby was transported to Dallas, where McClain performed the autopsy. To the doctor, the evidence pointed to sexual assault and murder.
"It is my opinion that Isis Charm Vas, a 6-month-old white female, died as the result of multiple blunt force injuries," McClain wrote in the autopsy report. (McClain declined to comment for this story.)
For police, solving the case was an exercise in elimination. Lopez was the only adult present when Isis collapsed. That made him the sole suspect. Who else could have done it?
In October 2001, a grand jury indicted Lopez on charges of capital murder and sexually assaulting a young child.
Trouble Examining Child Autopsies
Forensic pathologists like McClain play a critical role at the intersection of medicine and law enforcement. Employed by medical examiners and coroners' offices, they are called in to figure out how people have died. They scrutinize corpses, searching for clues. If a forensic pathologist says it's a homicide, police will soon be hunting for the killer.
Though depicted as glamorous and high-tech on TV shows such as CSI, the field of death investigation is plagued by chronic underfunding, a shortage of specialists, and a lack of national standards, according to a 2009 report by the National Academy of Sciences.
Many of the nation's morgues are staffed by doctors who aren't board-certified in forensic pathology. To become certified, doctors need an extra year of training and must pass a day-long test. Earlier this year, an investigation by NPR, ProPublica and PBS Frontline showed that more than 100 physicians without board certification were working at the country's busiest coroner and medical examiner offices.
Even for the best educated and trained doctors, performing an autopsy on a baby or young child poses particular technical challenges. Their developing bodies function differently. It's why doctors who treat living children — pediatricians — receive different training than those who deal with adults.
"Adults are generally tougher and harder to kill then a small child. Particularly an infant," said Jon Thogmartin, chief medical examiner for Pasco and Pinellas counties in Florida, a jurisdiction that includes St. Petersburg. "So, you're looking for very subtle signs of trauma or pressure, or small amounts of bleeding that could potentially cause a kid severe illness or death."
"Often there are only two pieces of evidence," said Justice Stephen Goudge, a Canadian judge who conducted an extensive inquiry into Ontario's forensic pathology system. "The first: who had care of the infant in the hours leading up to the death, normally a parent or caretaker. And secondly, the forensic pathology, which attempts to give an opinion on what the cause of death was." If the autopsy findings are flawed, the judge said, "then the risk of a miscarriage of justice is high."
Thogmartin said the charged emotions inevitably triggered by a child's death add another layer of complexity. Forensic pathologists, in his view, can get "caught up in the anger, the emotion, the despair." Their mindset can become prosecutorial, Thogmartin said, until every child death is a "homicide until proven otherwise."
Thogmartin overruled the autopsy conclusions in two child death cases handled by his predecessors that he said might have been colored by bias. In one case, a man was four years into a 10-year prison term for killing his infant son. In the other, a father was facing trial on murder charges for killing his 7-month-old daughter.
When Thogmartin sifted through the autopsy files and tissue samples, he was shocked: He saw no evidence of violence. In his opinion, the children had died of natural causes.
Both men were subsequently cleared by the courts, but even the one exonerated before standing trial suffered life changing consequences, Thogmartin said. "That unfortunate gentleman had his life turned upside down. ... His life was destroyed."
The Trial Of Ernie Lopez
The trial of Ernie Lopez began in April 2003.
Potter County prosecutors decided to try him only on the sexual assault charge; the capital murder charge was left pending, allowing prosecutors to try him for that offense at any time.
There were no witnesses to the alleged attack, and Lopez had not confessed, so the prosecution's case relied heavily on medical testimony. Over five days, a stream of doctors and nurses who had treated Isis at the hospital told the jury she must have been brutalized.
Eric Levy, who treated Isis in the hospital's pediatric intensive care unit, said the child's symptoms indicated she had been the victim of a violent attack. Looking at a photo of the baby's lower half, Levy pointed out bruise after bruise.
Michelle Gorday, a veteran nurse who specialized in sexual assault examinations, said it was one of the worst cases she'd witnessed in her 20-year career. "I've never ... ever seen that kind of trauma," she testified.
The defense called no expert witnesses. Lopez chose to take the stand, insisting he had never hurt Isis and testifying about the strange ailments that shadowed the last days of her life.
With each day, more health issues cropped up, he said. Blood spots speckled Isis' left eye. Congestion made it hard for her to breathe, prompting the Lopezes to treat the baby with a nebulizer. When Lopez changed her soiled diapers, her fecal matter, he testified, was "black" and "really thick and sticky."
DeAnn Lopez corroborated her husband's testimony.
Veronica Vas, Isis' mother, disputed the Lopezes' account, maintaining that Isis was only mildly ill before she died. "She had about six little bumps on the left side of her forehead, but those were already healing up," Vas testified. The baby's energy level was "quite normal."
Addressing the jury, Assistant District Attorney J. Patrick Murphy summed up the case by saying, "Common sense tells you who had to have done it. ... This child could not fight back. This child could not consent. This child could do nothing but lay there."
The jury found Lopez guilty. It was not until the sentencing phase of the trial that the jury learned Isis had died.
McClain, the medical examiner, testified she had ruled Isis' death a homicide. The baby, she said, suffered a "laceration of the vagina area" and injuries to her brain.
"In this case," McClain continued, "we know the head has struck something, because we've got bruising in that area."
Scrutinizing Isis' eye tissue under a microscope, McClain said, she had discovered more bleeding, which she interpreted as another possible indicator of violent head trauma. Seven other doctors in her office had reviewed the case and concurred with her findings, McClain added.
Lopez was sentenced to 60 years.
Reviewing The Medical Evidence
Heather Kirkwood was an unlikely candidate to take on Lopez's case. She had spent the bulk of her career litigating anti-trust cases for the Federal Trade Commission.
After learning about Lopez from a relative living in Texas, Kirkwood, who lives in Seattle, agreed to represent him. For her, Isis' death presented a fascinating jigsaw puzzle to solve. Lopez struck her as "a nice young man" and the "circumstances of the case seemed weird as hell."
"My gut sense kept telling me this was a sick baby who was neglected," she said.
Kirkwood started contacting physicians to analyze Isis' medical history. She sent a stack of documents to Richard Soderstrom, an emeritus professor of gynecology at the University of Washington. As an adviser to the Food and Drug Administration, Soderstrom served on a panel that studied the accuracy and safety of the colposcope, a device that can be used to take photos of injuries in sexual assault exams.
Isis Vas had been examined using a colposcope. After Soderstrom reviewed the photos taken of her, he gave a sworn affidavit stating that, in his opinion, the photos did not suggest there had been sexual abuse.
Kirkwood also approached Michael Laposata, the chief pathologist for Vanderbilt University Medical Center in Nashville and a leading expert on blood disorders.
To gauge how the blood is clotting, physicians typically begin with a pair of basic tests called the PT and PTT. In Isis, the "PT and PTT were markedly abnormal," Laposata said, adding that other tests also suggested a coagulation disorder. Where McClain had seen a "classic" case of blunt force trauma, Laposata saw something entirely different, a "classic picture" of Disseminated Intravascular Coagulation (DIC), a potentially lethal condition that can cause bleeding from sufferers' every orifice.
Based on the baby's "dark, tarry stools," elevated white blood cell count, and abnormal liver function tests, Laposata concluded, "something had to be going on for days" — long before the 40 minutes Lopez was alone with the baby.
An infection could have led to DIC, and, eventually, to a fatal collapse, Laposata said. DIC could also explain Isis' bruises and the bumps on her head that Lopez and others believed were spider bites, he added.
"The reality is when your blood is so thin, when you're so unable to make a clot, you can just develop bruises and they can be spontaneous," he said.
Diagnosing Child Abuse
There is a growing awareness among medical practitioners of "mimics": ailments that can cause the kind of bruising and bleeding once assumed to be telltale indicators of child abuse. A 2006 textbook on head injuries in children listed literally dozens of afflictions — including some fairly common illnesses — that can produce hemorrhaging in the brain.
This is just one way that the science of how children die has evolved in recent years. The most notable — and controversial — example of this is the intense debate over "shaken baby syndrome," which has played out in scientific journals and mainstream outlets such as the New York Times Magazine.
Based on studies dating back to the 1960's, many forensic pathologists — as well as other physicians — came to believe that a signature trio of symptoms provided definitive proof that someone had violently shaken a child. Under the theory, certain patterns of bleeding and swelling of the brain, and hemorrhages of the retinas came to be seen as conclusive evidence that a child had been assaulted with terrible force, even if there were no other signs of trauma.
But many experts now view the diagnosis with increasing skepticism. In Canada and Britain, official reviews have uncovered nine cases in which people may have been wrongly convicted based on the shaken-baby theory.
Case, the Missouri medical examiner, said the controversy is a "sideshow": Typically, children who've been shaken have also suffered other serious injuries from being battered. "Yes, there is a scientific debate," she said. "I personally believe that you can shake a child and kill it."
The thinking of other doctors has undergone a radical change. Patrick Barnes, a pediatric radiologist at Stanford University, was a key prosecution witness in what is arguably the most famous shaken-baby case of all, the trial of Louise Woodward. Woodward was a 19-year-old nanny charged in 1997 with shaking an 8-month-old baby to death, hitting his head and causing fatal bleeding. With Barnes' help, the jury found Woodward guilty of second-degree murder. (She was ultimately released after serving less than a year in prison, when a judge reduced her charge to manslaughter.)
Barnes said he wouldn't give the same testimony today. There's been a "revolution" in the understanding of head injuries in the past decade, in part due to advances in MRI brain scanning technology, he said. "We started realizing there were a number of medical conditions that can affect a baby's brain and look like the findings that we used to attribute to shaken baby syndrome or child abuse," Barnes said.
Overlooking Isis' Short Life
In prosecuting Ernie Lopez, law enforcement officials focused almost exclusively on Isis Vas' final hours.
Lopez's legal team looked back further, however, marshaling evidence suggesting that the baby's deteriorating condition might have been overlooked by her mother.
Veronica Vas had moved to Amarillo in 1995 to do her residency at a branch of Texas Tech University. She began dating a doctor, with whom she had two children. Then, in a subsequent relationship, Vas, 32, became pregnant with Isis. According to court testimony, Isis' father wasn't involved in her life.
The Vas household was chaotic in the period surrounding Isis' birth. That's clear from court records in the custody dispute between Vas and the father of her older children, as well as a statement submitted as part of the Lopez case.
Dena Ammons, a nurse who worked closely with Vas during her residency, said Vas changed during her pregnancy with Isis. She began showing up late for work, her hair matted and uncombed. In a sworn statement, Ammons said that Vas drank and smoked throughout the pregnancy.
Lorrie Word worked for Vas as a live-in nanny from August 1999 until the summer of 2000, caring for Isis from the time she was born. Word said in an affidavit that, on one occasion, she returned from her night off to find Isis alone in a darkened house, crying and soaked with urine. Vas would later say she only left the child for 10 minutes. Soon after the incident, Word quit her job.
Vas declined repeated requests for comment for this story. She has moved to Michigan, where the state medical board recently suspended her medical license due to alcohol abuse.
During Lopez's trial, Vas testified that in the months after Word quit she came to depend on the Lopez family to help care for her children.
According to Ernie Lopez, the day before Isis went into cardiac arrest he became so worried about the baby's health that he asked Vas for a note authorizing him or his wife to take the child to the doctor.
Vas didn't give him the note before leaving town for the weekend, he recalled in an interview. "Isis will be fine," Lopez said Vas told him.
Reopening The Lopez Case
By 2009, the new medical evidence gathered by Heather Kirkwood had captured the attention of the courts. After she filed an appeal, a habeas corpus petition, a judge granted Lopez a new evidentiary hearing. It represented a step toward possibly overturning his conviction.
The hearing lasted nearly twice as long as the original trial. This time, seven doctors testified —for free — on Lopez's behalf.
Kirkwood questioned Joni McClain, the forensic pathologist who ruled Isis Vas' death a homicide. McClain stood by her conclusion that Isis was killed by violence, not disease.
But she acknowledged that she'd paid little attention to Isis' blood-clotting tests and had only a vague understanding of their possible significance. "Did you look at these lab tests before reaching your conclusions?" Kirkwood asked. "I don't think I did beforehand because it was such a clear case of blunt force injury," McClain replied.
McClain admitted the tests went beyond her expertise as they can only be run on the living. "I don't get into a PT, PTT. It's a useless test after someone's dead," the doctor said.
Four other doctors testified for the state, saying Isis had died from blunt-force injuries, not a bleeding disorder. "This is a pattern of injury that we see with trauma," said Randell Alexander, a pediatrician who heads the child abuse division at the University of Florida's College of Medicine, in Jacksonville. "This is not a bleeding death."
McClain also argued that it was possible for head injuries to cause the type of clotting problems Isis had suffered.
In an interview, Laposata agreed head trauma can have that effect but said Isis' lab results were too abnormal to have resulted from an attack that allegedly occurred about an hour before her hospitalization.
It would be nearly a year before Potter County Judge Dick Alcala issued his opinion on the case. In August 2010, Alcala made a recommendation to the state's highest criminal court that Lopez's conviction should be overturned. He found that Lopez's original attorneys had failed to "fully investigate the medical issues of whether a sexual assault had occurred" and "the cause of death of the child." If they had investigated properly, Alcala wrote, the jury might not have convicted Lopez.
The judge rejected Lopez's claim of innocence, which would have required a conclusion that "no reasonable juror would have convicted him" — a high legal standard.
The case is now in the hands of the Texas Court of Criminal Appeals. It has the power to throw out Lopez's conviction and free him.
Potter County District Attorney Randall Sims continues to fight Lopez's appeal. In an interview, Sims said he could not discuss the case in detail because it is still ongoing. (He also said he had discouraged state witnesses, including the medical examiner, from speaking with us.) Sims said he thought Lopez had received a fair trial.
"The jury found him guilty," he said. "And we're defending that conviction."
There is no timetable for the appeals court's decision. Even if it overturns Lopez's conviction, he could remain tangled up in the criminal justice system for years. Sims could refile charges and try him a second time.
Eleven Years After Isis' Death
Behind the prison's thick cinderblock walls, Lopez struggles to hold onto what's left of his old life. Every Tuesday evening he calls his children collect, offering fatherly guidance despite the circumstances. He communicates less frequently with DeAnn, who divorced him and remarried after he was sent away.
Today, nearly 11 years after Isis died, Lopez continues to maintain — emphatically — that he never harmed her.
"Why should they believe that I'm innocent?" he asked during a two-hour interview. "Well, because that's not my character. That's not who I am."
Thinking back to that Saturday, Lopez paused and went silent, anguish filling his face. He exhaled heavily. "Her heart was beating a hundred miles an hour and she wasn't breathing. I put my ear to her chest, and I heard her heart just beating, just racing and ..." His head tilted downward and he stared at the floor. "She was there and then she wasn't there."
Lopez's voice grew quiet as the words trickled out slowly. "So many times," he said, "I think about what I could have done different to help her more."
NPR Investigations editor Anne Hawke edited and produced the radio stories.
Additional reporting contributed by Catherine Upin of PBS Frontline. ProPublica's Lisa Schwartz, Sergio Hernandez and Liz Day contributed research to this story.