The courtroom filled with applause.

After 11 years in prison and five rejected appeals fighting his 47-year sentence for a series of armed robberies in Los Angeles, Ruben Martinez Jr. was finally able to walk free.

In a courtroom full of Martinez’s family and friends, Los Angeles County District Attorney Jackie Lacey apologized. She said a “series of unfortunate and ultimately tragic circumstances” were the cause of his unjust imprisonment. Her office’s Conviction Review Unit finally made it possible for Martinez to prove his innocence after a close friend, who was a retired homicide detective, prevailed on prosecutors to take up his innocence claim and track down two new alibi witnesses.

“Whenever we receive new credible information that may exonerate a person, the responsibility is on us, as prosecutors, to re-examine the facts and, when appropriate, to vacate a wrongful conviction,” Lacey said in a tweet following Martinez’s exoneration.

Launched in 2015, the Conviction Integrity Unit in the LA District Attorney’s office is responsible for reviewing felony convictions for people who file claims of innocence. For a claim to qualify, the person filing the claim must be in custody at the time and there must be new credible evidence of innocence.

When it was first launched, nearly $1 million was approved for the unit, which Lacey said would pay for three prosecutors, a senior investigator and a paralegal. Now the CRU is comprised of four deputy district attorneys, two district attorney investigators, and one paralegal, according to a statement from Lacey’s office.

“The Los Angeles County District Attorney’s Office now joins prosecutors from Dallas to Denver, from Manhattan to San Diego, who have established conviction review units,” Lacey said in 2015. At the time, there were approximately 23 such units across the nation.

Four years later, they’ve continued to grow in number as prosecutors’ offices take on a role different from the traditional task of sending people to prison. Though still rare—out of the approximately 2,300 prosecutor offices in the country, there are 60 with a Conviction Integrity Unit—the units have helped release nearly 400 innocent people from prison.

Although the LA District Attorney’s Office is the largest prosecutor’s office in the nation, with 1,000 attorneys filing more than 71,000 felony cases annually, Martinez was only the third person to see his conviction overturned through the CRU.

Meanwhile, on the opposite coast of the U.S., Baltimore’s CIU completed its seventh, eighth, and ninth exonerations last month when three men walked out of prison after serving 36 years for a murder they were accused of as teenagers. Prosecutors now acknowledge those three men—Alfred Chestnut, Ransom Watkins and Andrew Stewart—were wrongfully convicted.

“I wouldn’t be surprised if there were hundreds of the same kind of people sitting in prison right now,” said Maryland State’s Attorney Marilyn Mosby in a New York Times interview.

Like the LA CRU, the Baltimore CIU was created in 2015. Although Baltimore County is less than one-tenth the size of LA, its CIU has exonerated three times as many wrongfully imprisoned people. Since it was launched, the unit has reviewed more than 1,900 claims, according to an emailed statement from Lacey’s office. Of those, 45 remain in various stages of review.

“District Attorney Lacey invested dedicated resources into establishing a Conviction Review Unit because she understands that the prosecution of a case is not perfect,” the statement said. “In a few instances, new evidence is discovered and, on rare occasions, mistakes are found.”

CIU’s vary widely in their effectiveness. California Innocence Project attorney Michael Semanchik said there hasn’t been any action on claims the organization has filed, though there are two pending. Given LA’s size, and studies which show that, conservatively, 4% of defendants are potentially innocent, he said it makes sense to look to cities of similar size as models for how active the LA CRU could be in exonerations.

“Generally in major cities the problem is somewhat consistent,” Semanchik said. “Look to New York and Chicago and see what’s happened in those CIU’s.”

According to the National Registry of Exonerations, the county in the U.S. with the most exonerations to date is Harris County, Texas, which encompasses Houston, with 141 exonerations. Cook County, Illinois, which includes Chicago, has the second highest number with 94 exonerations.

Of the number of exonerations in LA, Semanchik said, he would “expect it to be higher.”

Lacey’s office has pushed back against the implication that LA doesn’t do enough to exonerate people wrongfully convicted.

“Los Angeles County has a proven record of success in addressing systemic injustice when it becomes known, such as with the Rampart scandal,” Lacey’s office responded in a statement, referring to a widespread police corruption scandal in the LA Police Department in the late ‘90s. The probe into the fabrication of evidence, unprovoked beatings, planting of evidence, and other misconduct in the LAPD Rampart division brought 58 officers before an internal administrative board, resulting in 12 suspensions, seven resignations and five terminations. It also meant that 106 convictions were overturned. This was all before the creation of the CRU.

California Innocence Project director Justin Brooks looks to the Rampart scandal as a reminder from LA history to keep investigating the ways justice may have been mishandled—and an indicator of why there should be a more active conviction integrity unit.

“While I think the CRU is well-meaning, I am disappointed by the number of wrongful conviction cases that have been pursued by the LA district attorney’s office,” Brooks said. “LA is the largest county in the United States and the LA police dept has had several scandals, including Rampart, one of the most devastating scandals in the country. There are many more wrongful convictions that need to be looked at.”

Klara Stephens, a research scholar with the National Registry of Exonerations, again reiterated the expectation that the size of LA should paint a different picture.

“We know that Cook County and New York and Los Angeles have the three largest police forces in the country, but if you compare the number of exonerations in Cook County and New York and compare them with LA, the exonerations are much much lower in the conviction integrity unit,” Stephens said. “Unless there’s something extra special going on where LA doesn’t make any mistakes and the other places do, then there is either a lack of resources put toward the CIU or a lack of political will.”

To that point, according to Lacey’s office, “The CRU has not uncovered widespread incompetence or misconduct in Los Angeles County’s criminal justice system, as in other jurisdictions.”

Lacey’s office included in a statement a reminder that the office recently dismissed 900,000 infraction citations for “minor, quality-of-life, and moving violations,” and is also collaborating with Code For America to clear or dismiss more than 50,000 cannabis charges.

“She understands that the prosecution of a case is not perfect,” the DA’s office statement said. “In a few instances, new evidence is discovered and, on rare occasions, mistakes are found.”

Stephens said a growing number of conviction integrity units across the country are partially attributable to the election of more progressive district attorneys elected in various cities, but that even district attorneys without the “progressive” platform have prioritized these units.

Wayne County Prosecutor Kym Worthy in Detroit, for example, hired higher-ups appellate public defenders when launching the CIU there in 2018, which produced six exonerations that year. And Worthy is not a prosecutor who easily admits fault.

However, there are more examples of conviction integrity units like the one in LA, with very few or no exonerations. Twenty-eight have had zero, including counties encompassing the cities of Atlanta, Tucson and San Francisco.

“A lot of CIUs have opened up and we would say they’re nothing more than window dressing, a PR thing,” Stephens said.

Melissa O’Connell, a staff attorney at the Northern California Innocence Project, noted some of the cultural issues that can challenge the success of a conviction integrity unit. Access to prosecutorial records can be a strength, but with investigating staff who are part of the district attorney’s  office, it can complicate the incentives behind the unit. When the LA District Attorney’s Unit was first launched, Lacey decided against hiring lawyers with a defense background, which some legal experts advised to give the unit greater autonomy.

“It adds an interesting complication, if it’s an internal DA who’s assigned to the unit, they are being tasked with reviewing their colleague’s case, and that’s definitely a difficult position to be in,” O’Connell said.

Still, O’Connell sees promise in the growing acceptance of conviction integrity units as a sign of a “national shift” in the country’s recognition that the system is flawed. The success of a conviction integrity unit comes from the top, and requires a shift in how people think of the “strong prosecutor.”

“It takes good strong prosecutors to acknowledge that we’ve learned over the last 30 years, and they’re in a position where they can rectify those wrongs,” O’Connell said. “They are in a position to make innocent or conviction integrity units part of their platform to say not only are we going to make sure our community safe, but we also want to rectify the wrongs that we know happen.”  

Alex Arriaga is a reporter and writer based in Chicago. Her work focuses on how people engage and participate in democracy and how community reporting can empower that participation in different ways....