Walter Barton: New blood stain evidence suggests man may be innocent days before execution

Walter Barton is scheduled for execution on 19 May

Newly released blood spatter evidence has cast doubt on a murder conviction for an inmate who is scheduled to be executed in three days.

Three jurors who convicted the man said that new blood spatter evidence has raised doubt about his guilt.

Walter Barton, 64, was convicted of killing an 81-year-old woman who managed a mobile home park in Missouri. He was sentenced to death and is scheduled to be executed on 19 May.

According to the Kansas City Star, crime scene analyst Lawrence Renner offered expert testimony that argued that the blood stains were not made from an impact, but were rather evidence of transfer, likely the result of Mr Barton touching existing stains.

Mr Renner said that the killer would have been covered in the victim's blood.

The victim, in this case, was Gladys Kuehler, who was beaten and sexually assaulted before being stabbed more than 50 times. A stain appearing on Mr Barton's clothing was a DNA match for Ms Kuehler.

Mr Barton's attorney said his client had blood on his shirt because he was one of the individuals who helped identify Ms Kuehler's body. He said he was with Ms Kuehler's granddaughter when the pair knocked on the 81-year-old's trailer door and found her dead in a blood-soaked bedroom.

When officers arrived, they spotted spots of blood on Mr Barton's clothes. He claimed he must have gotten the blood droplets on him when he slipped while pulling Ms Kuehler's granddaughter away from the body.

The granddaughter's initial testimony confirmed Mr Barton's story, but she later changed her story, saying Mr Barton had never entered the bedroom.

Now, a quarter of the jurors who sentenced Mr Barton to death are having second thoughts.

Three of the 12 have signed an affidavit confirming that had Mr Renner's testimony been available during the initial trial, it would have affected their deliberations. One member said they had "serious questions" regarding Mr Barton's guilt.

The jurors agreed that the blood stain evidence was the prosecution's "strongest evidence" in its case against Mr Barton.

Mr Barton has consistently maintained his innocence.

The state of Missouri released a statement last week announcing it intended to go ahead with Mr Barton's execution. The state's Attorney General's Office said Mr Renner's testimony "does not come close" to changing the trial's outcome.

In April, the state's Supreme Court denied Mr Barton's request for a hearing to argue his innocence and his possible impairment by a brain injury.

Three years after Mr Barton's conviction in 2006, the National Academy of Sciences published work undermining the credibility of blood stain analysis, characterising it as "more subjective than scientific" and concluding that "the uncertainties associated with bloodstain-pattern analysis are enormous."

During the initial trial in 1993, the state of Missouri's own blood spatter analyst offered testimony that influenced the jurors' decision to convict. Mr Barton's defence team attempted to undermine the testimony as "junk science" at the time.

"It's a nightmare because the original case against Mr Barton was a close one," Frederick Duchardt Jr, Mr Barton's defence attorney, said. "It is a worse nightmare because evidence, never heard by the jury who rendered judgement, undermines the key evidence used to convict.