A Texas man this week could become the first person executed in the U.S. from a murder conviction tied to the diagnosis of shaken baby syndrome.

Robert Roberson, 57, is scheduled to receive a lethal injection on Thursday for the 2002 killing of his 2-year-old daughter, Nikki Curtis. Roberson has long proclaimed his innocence. His lawyers as well as a bipartisan group of Texas lawmakers, medical experts and others have argued his conviction was based on faulty scientific evidence and say new evidence has shown Curtis died from complications related to severe pneumonia.

But prosecutors maintain Roberson’s new evidence does not disprove their case that Curtis died from injuries inflicted by her father.

Roberson’s scheduled execution renewed debate over shaken baby syndrome. On one side of the debate are lawyers and some in the medical and scientific communities who argue the shaken baby diagnosis is flawed and has led to wrongful convictions. On the other side are prosecutors and medical societies from the U.S. and around the world who say the diagnosis is valid, has been scientifically proven and is the leading cause of fatal head injuries in children younger than 2 years of age.

Here’s what to know about the highly scrutinized diagnosis ahead of Robertson’s scheduled execution:

What is shaken baby syndrome?

The diagnosis refers to a serious brain injury caused when a child’s head is injured through shaking or some other violent impact, like being slammed against a wall or thrown on the floor, usually by an adult caregiver, said Dr. Suzanne Haney, a child abuse pediatrician and member of the American Academy of Pediatrics Council on Child Abuse and Neglect.

The term was changed in 2009 to abusive head trauma, a more inclusive diagnosis, Haney said.

There are about 1,300 reported cases of shaken baby syndrome/abusive head trauma in the U.S. each year, according to the National Center on Shaken Baby Syndrome.

What is the debate over shaken baby syndrome?

Critics allege doctors have been focused on concluding child abuse due to shaken baby syndrome whenever a triad of symptoms — bleeding around the brain, brain swelling and bleeding in the eyes — was found. Critics say doctors have not considered that things like short falls with head impact and naturally occurring illnesses like pneumonia, could mimic an inflicted head injury.

“The shaken baby syndrome/abusive head trauma hypothesis that was used against Mr. Roberson is not science, plain and simple,” said Kate Judson, executive director of the Center for Integrity in Forensic Sciences, a Wisconsin-based nonprofit that seeks to improve the reliability of forensic science evidence.

While Haney declined to comment on Roberson’s case, she said there is no disagreement within a vast majority of the medical community about the validity and science behind the diagnosis.

Haney said doctors are not just focused on a triad of symptoms to determine child abuse, but instead look at all possible things, including any illnesses, that could have caused the injuries.

“I worry the pushback against abusive head trauma as a diagnosis is going to interfere with the prevention efforts that are out there and therefore allow more children to get harmed,” Haney said.

What are the concerns Roberson’s supporters are raising?

Roberson’s attorneys say he was wrongly arrested and later convicted after taking his daughter to a hospital. She had fallen out of bed in their home in the East Texas city of Palestine after being seriously ill for a week.

New evidence gathered since his 2003 trial shows his daughter died from undiagnosed pneumonia that progressed to sepsis and was likely accelerated by medications that should not have been prescribed to her and made it harder for her to breathe, said Gretchen Sween, Roberson’s attorney.

The Anderson County District Attorney’s Office, which prosecuted Roberson, has said in court documents that after a 2022 hearing to consider the new evidence, a judge rejected the theories that pneumonia and other diseases caused Curtis’ death.

What have courts said about shaken baby syndrome?

In recent years, courts around the country have overturned convictions or dropped charges centered on shaken baby syndrome, including in California, Ohio, Massachusetts and Michigan.

In a ruling last week in a different shaken baby syndrome case out of Dallas County, the Texas Court of Criminal Appeals ordered a new trial after finding scientific advancements related to the diagnosis would now likely result in an acquittal in that case.

But the appeals court has repeatedly denied Roberson’s request to stay his execution, most recently on Friday.

In the U.S., at least eight individuals have been sentenced to death because of shaken baby syndrome, said Robin Maher, executive director of the Death Penalty Information Center. Two of these eight have been exonerated and Roberson is the only one to have received execution dates.

“According to the National Registry of Exonerations, at least 30 people across the country have been exonerated based on this discredited scientific theory,” Maher said.

But Danielle Vazquez, executive director of the Utah-based National Center on Shaken Baby Syndrome, said a 2021 research article found that 97% of more than 1,400 convictions related to shaken baby syndrome/abusive head trauma from 2008 to 2018 were upheld and that such convictions were rarely overturned on the grounds of medical evidence.

“Take away all these different cases and … there are still brand-new parents that are extremely tired, can be extremely frustrated with a crying baby and might not act appropriately when caring for that child. And so that’s our big concern, that misconception that shaking a baby is OK,” Vazquez said.

(AP)