‘I made a mistake’ - Medical examiner changes homicide finding, but convicted woman still behind bars

Advancing technology shows that some “shaken babies” may have died of illness or hereditary disorders
Reporter: Andy Pierrotti, Videographer/Editor: Luke Carter
Published: Oct. 3, 2022 at 2:13 PM MST
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BILOXI, Mississippi (InvestigateTV) – For decades, Tasha Mercedes Shelby had been proclaiming her innocence in the death of her 2-year-old stepson before someone finally believed her: the doctor whose own testimony sent the young woman to prison for life.

“I made a mistake,” former Mississippi state medical examiner Dr. Leroy Riddick testified in 2017.

Yet, Shelby remains behind bars.

Her story mirrors uncounted others who have been convicted of a homicide charge, alleging a child died of Shaken Baby Syndrome, but advancing pediatric medicine now suggests that those kids may have died from medical conditions.

“No one shook this child. No one abused this child,” said Valena Beety, Shelby’s attorney. “The jury was relying on the wrong information.”

Shelby’s story begins in Biloxi, Mississippi in 1997.

On June 1, 1997, Shelby was sleeping in her bedroom when a loud thump awakened her. She got up and found her 2-year-old stepson, Bryan Thompson, lying on the floor of his bedroom, having what looked like a seizure, police records show.

A police report details what Tasha Shelby told officials, including how she believed she saw...
A police report details what Tasha Shelby told officials, including how she believed she saw her stepson having a seizure.(Graphic by Luke Carter)

Dr. Riddick, the medical examiner in Harrison County, didn’t believe her story and ruled Bryan’s death as a homicide, saying the child died by a blunt force trauma caused by shaking.

She was just 25 years old, with no prior criminal record, when she was sentenced to life in prison with no chance for parole.

Eighteen years later, Shelby’s lawyers asked Riddick to re-examine his findings in the case.

“I made a mistake on my conclusions and that given the information I have now, that the child died from hypoxic encephalopathy with herniation due to a seizure disorder,” the doctor said when asked if he would tell prosecutors and detectives anything differently today.

“Hypoxic encephalopathy with herniation” means the doctor believes the child suffered from a lack of blood and oxygen to the brain.

Dr. Riddick said he made a mistake and in 2018, he changed the boy’s death certificate to say that the cause of death was an “accident.”

Dr. Leroy Riddick's said under oath in 2017 he believed his original diagnosis was a "mistake,"...
Dr. Leroy Riddick's said under oath in 2017 he believed his original diagnosis was a "mistake," and that 2-year-old Bryan Thompson's death was an accident.(Video still obtained by InvestigateTV)

Today, Riddick can’t say why he changed Bryan’s manner of death. He passed away nearly two years ago.

According to Beety, Shelby’s attorney, Riddick testified in hundreds of cases during his career and Shelby’s case is the only one where he changed his opinion.

“We thought, they’re going to let her go. There was no homicide. You can’t keep someone in prison if there was no homicide,” said Penny Warner, Shelby’s aunt.

But the judge in the case wasn’t persuaded.

In 2018, a Harrison County circuit court judge declined her appeal based on Riddick’s change of opinion. The judge believed Riddick’s June 2000 testimony instead of his new opinion.

“Shaken baby syndrome may have been involved in legitimate debates in the years since Bryan’s death and Shelby’s trial but it has not been ‘debunked’ as alleged,” wrote Judge Roger Clark.

This past July, Beety filed a new petition in the U.S. District Court for the Southern District of Mississippi, asking a federal judge to dismiss Shelby’s case.

The office of Mississippi Attorney General Lynn Fitch opposes the appeal. A spokesperson declined to comment on the case.

The district attorney’s office that originally prosecuted her case also did not respond to interview requests.

A change in science leads to exonerations

Since 2015, prosecutors have charged at least 3,000 people with abuse or murder connected to the “Shaken Baby Syndrome” diagnosis, according to the Medill Justice Project at Northwestern University.

But the diagnosis, now more commonly identified as abusive head trauma, is riddled with controversy.

It’s diagnosed through a triad of symptoms: bleeding in the retinas of the eyes, bleeding under the dural matter of the brain (subdural hematoma) and brain swelling— all occurring in the absence of a recent car accident or other clear explanation for the injuries.

Today, new science shows those same injuries can also be linked to illnesses and biological issues, like seizure disorders.

Riddick said in 2017 the new scientific opinions compelled him to change Bryan’s death certificate.

“Severe seizures that are lasting for a period of time, that the brain stem is shut off, and you don’t breathe and then you get hypoxia ... If you don’t get enough oxygen to your brain, then you die,” said the medical examiner during the deposition.

While Tasha Shelby waits for the federal court to rule on her case, InvestigateTV uncovered at least 21 people charged with crimes connected to Shaken Baby Syndrome diagnoses who have had their convictions overturned since 2019.

Experts attribute the change in science to most of the case dismissals.

According to a database run by the National Registry of Exonerations, there even more defendants falsely convicted on the flawed diagnosis.

One of them includes Sabrina Butler, who was sentenced to death in 1990 for killing her son, Walter.

She served five years at the same Mississippi prison where Shelby is currently detained. She wase exonerated five years later when it became clear her son died from a rare genetic disorder that ran through her family.

The Mississippi prison where Butler served time, and where Shelby is currently incarcerated.
The Mississippi prison where Butler served time, and where Shelby is currently incarcerated.(InvestigateTV)

This January, a superior court judge in New Jersey prevented state prosecutors from introducing Shaken Baby Syndrome diagnosis as evidence based on its unreliability. The case involved a father accused of shaking his 11-month-old son. Judge Pedro J. Jimenez, Jr. wrote in his ruling that the diagnosis of is “an assumption packaged as a medical diagnosis” and “lacks scientific grounding.”

Daniel Mullen is one of the jurors who voted to convict Shelby more than 20 years ago.

“The first time around, it was a unanimous vote that she was guilty,” said Mullen during an interview with InvestigateTV in July outside Biloxi.

Two decades later, Mullen now believes Shelby is innocent after learning about Bryan’s disorder and the family’s history of seizures.

According to the original trial’s court transcripts, Thompson had an appointment scheduled with a neurologist before his death that he never made, important details Mullen doesn’t remember as a big part of the case.

All of the evidence resonates with the former juror because his son suffered from violent seizures as a child. “When I start talking about seizures I tear up. It’s something you don’t want to see,” said Mullen.

Mullen said he would not have convicted her based on what he knows today. “I think she’s innocent. I think the baby had a seizure and she panicked and didn’t know what to do,” said Mullen.

Another shaken baby case under appeal

This past May, family and friends of Danyel Smith protested his 2003 conviction outside a courthouse in Gwinnett County, Georgia.

Smith is serving life in prison, convicted of shaking his two-month-old son, Chandler, to death.

Newspaper coverage by the Atlanta Journal Constitution from 2003.
Newspaper coverage by the Atlanta Journal Constitution from 2003.(Graphic by Luke Carter)

“If that was your son being in prison for 20 years for something he had not done, what would you do?” said Smith’s mother at the protest.

Today, one pediatric neurosurgeon believes Chandler’s death was caused by trauma during birth, according to court records recently filed in the case. Chandler was born premature at 35 weeks. Transcripts from the original trial show Chandler’s mother called 911 about a month before the boy’s death after she thought he had a seizure. She said paramedics dismissed her concerns.

This past March, a superior court judge refused to grant Smith a new trial. Attorneys with the Southern Center for Human Rights represent Smith. They have appealed the decision with the Supreme Court of Georgia.

LaTasha Pyatt, Danyel’s fiancé, said she thinks he is innocent.

“I know deep down in my soul that he did not do this,” said Pyatt, who is not related to the deceased child. “I don’t look at the calendar until you force my head to look. I don’t even look at it because there is an innocent man in prison that needs to be home with his family.”

Last year, a judge in Columbus, Ohio freed a woman who had served 18 years in prison in a shaken-baby case. The coroner who testified at her trial in 2002 changed his ruling after discovering in 2018 that the child had brain bleeds that caused her death.

Back in Mississippi, Shelby’s fate hangs on a federal judge releasing her from prison or Mississippi’s governor granting her clemency.

Shelby wanted to share her story with InvestigateTV on-camera, but Mississippi’s Department of Corrections refused to allow her to do an interview.

However, InvestigateTV was able to speak with her by phone. You can watch the full conversation below:

Reporter: Andy Pierrotti, Videographer: Owen Hornstein, Producer: Emily Featherston, Graphics: Luke Carter