Man falsely convicted by bite mark didn't kill Dallas couple, DA now says

Steven Mark Chaney hugged his mother, Darla Chaney, after being released from prison in October at the Frank Crowley Criminal Courts Building. Behind them is his wife, Lenora Chaney.

It's probably only a matter of time before Texas' courts declare Steven Mark Chaney's innocence in a murder that used faulty evidence to convict him.

The Dallas County district attorney's office now agrees, as does the former prosecutor who sought the conviction, that there is no way Chaney should have been convicted or even indicted in the 1987 stabbing deaths of John and Sally Sweek.

At a hearing Tuesday, the former prosecutor, Neil Pask, testified that although he believed that bite mark evidence in the case linked Chaney to the crime at the time of the trial, he now believes it to be bad science, Chaney's attorney Julie Lesser said.


Julie Lesser, a Dallas County public defender (Evans Caglage/Staff)

The case was already on its way to dismissal, but it faced a long path through the Texas court system. The effort just got a little easier: The Texas Court of Criminal Appeals, the highest criminal court in Texas, is likely to side with Chaney and the district attorney's office and declare him "actually innocent."

To Chaney, the move means people are acknowledging he didn't do it, said Lesser, a Dallas County public defender who worked on the case with the Innocence Project in New York. 

It has bothered Chaney that previously "it sounded like he got off on a technicality,"  Lesser said. "He wants his name cleared." 

Patricia Cummings, the head of conviction integrity at the DA's office, said that when Pask testified that he now believes Chaney is innocent, it was "a pleasant surprise. I admired him for doing it. It took a lot of guts."

"I think he wanted to publicly apologize."

Pask could not be reached for comment Tuesday.

The district attorney's office is again investigating the death of the Sweeks to determine the true killer. The office has found "quite a bit of evidence pointing to other perpetrators," Cummings said. But no arrests have been made.

Chaney, a 60-year-old former construction worker, was released in October after serving nearly 30 years behind bars. State District Judge Dominique Collins brought him pumpkin pie to celebrate that day. She wanted to give him something tasty to eat after decades of prison food.

The case

The Dallas County district attorney's office became the first in Texas to declare bite mark evidence "junk science." Earlier this year, Texas became the first state to do the same when the state's forensic science commission recommended a ban.

Today, throughout the state, few prosecutors use bite mark evidence. Usually, they search for DNA in the bite marks or use it as secondary evidence. 


The driving force behind Chaney's conviction was the testimony of forensic dentists. That testimony, some scientists now say, is among the shoddiest of junk science.

During Chaney's trial, prosecutors said he murdered John Sweek to avoid paying a large debt to the drug dealer.

Prosecutors hired two forensic dentists who said they spent hours matching molds of Chaney's teeth to bite marks on Sweek's arm.

Dentist Jim Hales told a Dallas County jury that there was a "1 to a million" chance that someone other than Chaney made the bite marks on Sweek's body. Hales now says the science used to convict Chaney has been discredited.

"Conclusions that a particular individual is the biter and their dentition is a match when you are dealing with an open population are now understood to be scientifically unsound," Hales said in an affidavit.

Chaney's jury believed the forensic dentists over nine witnesses who said they had spent time with Chaney the day of the slayings and that he couldn't have been at the Sweeks' home when they were killed. At least one juror said after the trial that the bite evidence convinced her that he was guilty.

Since 2001, more than 30 men in Dallas County have been exonerated of crimes they were wrongly convicted of committing. Most of the cases were overturned using DNA evidence. Some, like Chaney's, relied on other evidence.

The Associated Press reported in 2013 that at least 24 people in the U.S., including two in Texas, had been exonerated in cases in which bite mark evidence played a central role in the conviction.

Chaney's attorneys and the district attorney's office also agreed that evidence was withheld in the case. 

At trial, prosecutors presented false evidence that blood had been found on the bottom of Chaney's tennis shoe. There was not a sufficient amount to determine whether it was blood. Notes were withheld from another expert who said there was no blood on Chaney's shoes. Prosecutors also did not turn over several conflicting statements given by trial witnesses.

Police searched Chaney's car and home for blood, especially hoping to find blood on his jeans. When they didn't find any, they didn't file a report and didn't tell prosecutors. 

"The absence of blood during the searches undermines the state's theory that there would have been blood everywhere" after the murders, Cummings said.

Lesser said that Pask, in sworn testimony, said police did not turn over the complete file or that he did not actively pursue the file. 

Prosecutors are required by the U.S. Supreme Court to turn over any evidence that is favorable to the defendant. Not handing over such evidence is called a "Brady violation," based on the high court's Brady vs. Maryland ruling. Several other Dallas County exonerations have involved cases where evidence was withheld.

Chaney's case will soon be forwarded to the Texas Court of Criminal Appeals, which has no deadline for a ruling.

Adam Lee Nemann
Connect with me
Trial and Defense Attorney, Adjunct Professor of Law at Capital University, founder of Nemann Law Offices
Post A Comment

Blood Alcohol Calculator