When Illinois jurors convicted Patrick Pursley of murder, they relied on an expert’s assurance that the scratches and dents on bullets and shell casings from the crime scene proved they could only have come from Pursley’s gun.
More than two decades later, technological advances have eroded confidence in ballistic experts, and the analyst who testified against Pursley is no longer so sure of his findings. Now Pursley is awaiting a new trial, and the case could become the first in which a database used to help put countless criminals behind bars sets someone free. The issue could also pave a new path for other convicts to challenge convictions.
“I knew that this could exonerate me because there would be no bias. It would just be a computer algorithm saying it is or it isn’t,” said Pursley, who was convicted in 1994.
Now 51, Pursley represented himself for more than a decade and convinced Illinois legislators to update the law to let him retest the evidence using a more advanced system that links shell casings to guns — a tool that became available five years after his conviction.
A judge agreed that the results from the Integrated Ballistic Identification System cast doubt on the trial expert’s conclusions. Pursley was granted a new trial in March.
The system known as IBIS compares high-resolution, multi-dimensional images of shell casings to find markings unique to a specific weapon. In Pursley’s case, it failed to match the gun police took from him to the bullets that killed 22-year-old Andy Ascher on April 2, 1993, in Rockford, northwest of Chicago.
It’s not clear how many cases like Pursley’s exist. So far, Illinois is the only state that allows the system to be used in appeals. Pursley is the first to use the 2007 law, “which could set an important precedent for others,” said Andrew Vail, an attorney at the law firm representing Pursley for free along with Northwestern University’s Center on Wrongful Convictions.
Steven Drizin, the assistant dean at the center, said he’s hopeful other states will update their laws.
“This is pretty much uncharted territory and it shouldn’t be,” Drizin said.
The images placed into IBIS are stored in the National Integrated Ballistic Information Network managed by the Bureau of Alcohol, Tobacco, Firearms and Explosives. Since 1999, the 2.8 million images entered into the database have helped investigators identify suspects in countless homicides nationwide, according to the ATF, which lists success stories on its website .
Winnebago County prosecutors are appealing the judge’s ruling for a new trial. They maintain that Pursley was the man who approached Ascher and his girlfriend while they sat in a car and demanded money. Ascher’s girlfriend told police she was looking for cash in her purse when she heard two shots and saw Ascher slouch down in the driver’s seat. The gunman wore a blue ski mask and black gloves, according to Ascher’s girlfriend, but police never found either item.
Since Pursley’s first trial, at least five convictions nationwide that relied on ballistic evidence have been overturned, according to the National Registry of Exonerations.
Without the technology, matching bullets to firearms requires an expert to manually compare photographs of shell casings from a crime scene to shell casings test-fired from a gun.
IBIS can produce “high confidence” matches, but someone still must analyze them under a microscope. And even ballistic experts who believe in the accuracy of their craft acknowledge that it’s reckless to declare their results with absolute certainty because it’s impossible to examine every gun in the world.
When prosecutors made their case against Pursley, the only physical evidence they presented to connect him to Ascher’s homicide came from ballistics expert Daniel Gunnell. Using a microscope far weaker than those available now, he told jurors Pursley’s gun was the murder weapon “to the exclusion of all other firearms.”
But during a three-day hearing in December, Gunnell said he “would not testify the same way today” and that the language he used then “could give an inappropriate opinion” to listeners.
Gunnell and the Winnebago County State Attorney’s Office declined to comment to The Associated Press because the case is ongoing.
Pursley had run-ins with police long before he was charged with murder. He was 14 when his mother gave him up to the Illinois Department of Children and Family Services because, he said, he was skipping school and smoking marijuana. He said he was shuffled between homes in Chicago and Rockford and joined a gang. Once he was no longer in the state’s custody, he was in and out of prison for burglary and drug possession.
After he was convicted in Ascher’s death, Pursley faced the death penalty but received a life sentence instead. In prison, he began taking courses in law and helped inmates with appeals. He also developed a website aimed at helping at-risk youth — a project he hopes to continue to work on.
He achieved some key victories on his own before obtaining legal representation. He got a court to preserve his gun and the bullets from the crime scene in 2005, which made the IBIS testing possible. Around that time, he learned Illinois’ post-conviction law had to be updated to allow for IBIS testing so he sent letters to Illinois lawmakers.
His pleas went unanswered until an activist for inmates, Bill Ryan, took his idea to Chicago Democratic state Rep. Art Turner Sr.
“He started to say that if he could prove that it wasn’t his gun that it would show his innocence,” said Ryan, 83. “I frankly wasn’t sure. A lot of guys tell me that stuff.”
After the law passed, Pursley finally got legal representation. But even with lawyers, it’s been a slow process. It wasn’t until 2011 that a court ordered that the ballistic evidence be re-examined and five more years before his hearing for a new trial.
He is free on bail while awaiting the trial. Pursley put himself in jeopardy of going back to prison after recently testing positive for marijuana. He could have his $50,000 bail revoked or increased at an Oct. 3 hearing.
He said he doesn’t feel free because the case isn’t over.
“It’s like the pit and the pendulum,” he said. “This way or that way. Which way? … It’s a lot of pressure.”