It took only a single eyewitness testimony to convince a jury to wrongfully convict Stephen Patterson to a 50-year life sentence for shooting and killing 16-year-old Yair Oliva in 2005. That witness was 200 yards away, inside her home in South Los Angeles and peering through closed blinds.
Other witnesses contradicted that testimony or could not identify Patterson, who was only 19 at the time. Investigators also ignored that the gun used in Oliva’s killing showed up at another crime scene six weeks later.
But on Wednesday, Patterson was declared innocent after spending nearly half his life behind bars. His exoneration marks the 13th under Los Angeles County District Attorney George Gascón’s tenure. According to his office, those 13 people collectively add up to nearly 300 years of wrongful incarceration.
Gascón is running for reelection and touting his work on criminal justice reform that his competitors have criticized as being soft on crime.
"I had a lot that I wanted to say," Patterson said during his news conference. "Especially for the people still waiting on their turn to be freed who have been falsely imprisoned. But when I heard 300 years, it broke my spirit. That's a long time, and it's minorities, and it's overlooked."
Patterson’s mother hired a private investigator, Eduardo Hernandez, before the Innocence Center got involved and reinvestigated. The effort led to filing a conviction review request with the district attorney’s Conviction Integrity Unit. The team examines and reinvestigates wrongful conviction cases and remedies them. It has received 886 requests for review between 2020 and 2023.
Los Angeles is one of the top five counties with the most exonerations nationwide. At least 50 have happened within the county since 1989 with help from innocence organizations.
When former L.A. County District Attorney Jackie Lacey created the Conviction Integrity Unit (CIU) in 2015, criminal justice reform advocates had high hopes that it would lead to change within the system that incarcerates Black and Latino people at substantially higher rates than white people. But under Lacey’s watch, the CIU exonerated three people from its inception through the end of her tenure in 2020.
Gascón has more than tripled the amount of exonerations since taking office in 2020. He calls Maurice Hasting’s case a “parting of the waters” moment. Hastings served nearly four decades in prison for the rape and murder of Roberta Mydermyer in 1983 that he did not commit. Gascón tested DNA evidence that was previously reported as destroyed. That testing eventually proved Hasting’s innocence.
“Keeping the integrity of the conviction is sort of ignoring the facts, hiding evidence in order to continue the conviction to stand. I think it's a very perverse way of looking at the integrity of the system,” Gascón said. “And, more importantly, once it was tested, it showed that he was not the person that committed the rape on the murder.”
In the same case, DNA evidence revealed that Kenneth Packnett murdered and raped Wydermyer. Packnett went on to sexually abuse more women before getting sent to prison.
The Innocence Center’s executive director, Mike Semanchik, said he had to go to court and fight for every single exoneration a decade ago. But now he can present his case to one of 10 conviction integrity units statewide, who then do their investigation and then decide whether a wrongful conviction occurred.
“That's kind of where the change in tide has sort of happened,” Semanchick said. “There was always this belief in finality, and I think that’s flawed. The belief should be in justice. We should be thinking we got it right, and in so many of these cases that we do, we find the true perpetrator who goes on to commit more crimes.”
But if you ask Semanchick if the system has gotten better at not wrongfully convicting people, he said it's hard to say. If he’s lucky, a case can take three or four years to reach his desk after a trial. He said wrongfully convicted people spend and average 16-and-a-half years in prison before their conviction is reversed.
Maurice Possley is a senior researcher with the National Registry of Exonerations, a nonprofit that tracks wrongful convictions. He said people who advocate for conviction integrity units attempt to bring equity and fairness into the criminal justice system.
“Black and brown people are seven times more likely to be wrongfully convicted,” he said. “It's a fact of life.”
And when a district attorney stands behind criminal justice reform, Possley said things start to happen — and the numbers back it up. He points to 114 exonerations nationwide in 2000. Fast forward to 2023, and the number jumps to 153.
“The good news is people are getting exonerated,” he said. “The bad news is people still have to get exonerated.”
Semanchik said this nonprofit estimates there are at least 5,000 innocent people in California prisons right now, but the number could be as high as 10,000. Last year, state Attorney General Rob Bonta announced the creation of a Post-Conviction Justice Unit, a team that aims to investigate wrongful or improper convictions.
Semanchik said it’s taking time to staff up the unit and figure out which cases to review. But he added that progress is being made and hope is there.
The L.A. County District Attorney’s Office says 117 cases are currently under review. But in a perfect world, Gascón said conviction integrity units should be a statewide initiative.
“Not every district attorney's office is going to have the willingness or the capacity to do this,” Gascón said. “Certainly, we have a lot of wrongful convictions in L.A…we’re not unique. There’s 57 other counties, and there needs to be accountability at the very top of the state.”
