MARY LOUISE KELLY, HOST:

In California, a new transparency law is shedding light on a long-hidden world - the world of police investigating police actions. Journalists analyzed records from 122 departments across the state. What they found - one in 10 failed to review deadly use of force incidents. In other words, they're not reviewing how police officers acted and why when they kill someone or badly injure someone. Sukey Lewis of member station KQED is one of the journalists who has been combing through the record. She joins us now.

Hi, Sukey.

SUKEY LEWIS, BYLINE: Hi.

KELLY: So how did you and your colleagues uncover this - that some agencies are aren't investigating these incidents at all?

LEWIS: Well, my colleague Thomas Peele at the Bay Area News Group and I - I think when we went into this, we assumed that these agencies would always do this kind of review, especially in cases where someone died because these investigations are how departments identify problems or impose discipline on somebody. And so we first thought that these departments were just withholding records, and it was stunning to find out - you know, not just to me, but to some law enforcement sources - that they actually weren't doing them.

KELLY: Just not standard practice - now, in terms of the ones you decided to look at - I mentioned you looked at 122 law enforcement agencies out of more than something like 500 in the state of California. Why did you pick the ones you did?

LEWIS: So we were looking at agencies that both had had a deadly use of force incident in the past five years and had provided us records, so this analysis is not yet comprehensive statewide.

KELLY: Let me focus you on one example to bring to life some of the stuff you were uncovering. There's a particular case in the Bay Area town of Pittsburgh that I know you were focused on. Walk me through what happened there.

LEWIS: So this was a case in which an officer used a neck restraint on a subject who was resisting arrest, and the man, Humberto Martinez, you know, died as a result of that hold. And this was a really similar case in a lot of respects to the death of Eric Garner in 2014...

KELLY: Yeah.

LEWIS: ...At the hands of a New York City police officer.

KELLY: The I can't breathe case - his famous last words.

LEWIS: Yes. And that case, the Garner case and others like it had sparked this huge national debate about the use of neck restraints, which can really easily be done improperly and be deadly. But here in Pittsburgh, they didn't even look at if the hold was done wrong, how it had turned deadly or what could have been done differently. And the police chief there, Brian Addington - he wouldn't comment on the case because the city is being sued over it. But at least one thing has changed in the years since that happened, which was in 2016. You know, now internal reviews of these kinds of incidents are mandatory.

KELLY: Let me pause you there because I think you're touching on an important distinction between a potential criminal case against a police officer and then internal reviews that might inform the way these departments are run going forward.

LEWIS: Yes. So a lot of these agencies that didn't do internal reviews said, we just relied on the DA's investigation. But the aim of the district attorney's criminal inquiry is to figure out if a cop committed a crime when they shot at somebody or used force on a subject. But that's a really high bar, right? The goal of an administrative review is really different. You know, one expert I talked to who worked in internal affairs for years and trains other officers said this process is an opportunity, you know, not just for departments to discipline officers who break their rules, but also to look back at these critical incidents in order to learn from them and potentially prevent deaths in the future.

And I also just wanted to point out that the cases we looked at - you know, some of them were pretty straightforward. I dont want to, you know, misrepresent them and say that they all pointed to misconduct of some kind. But the expert that I talked to said it doesn't even matter. It's, like, something that should be looked at every single time so that these lessons can be learned. And even if everything was done right, that also teaches you something.

KELLY: Reporting there from Sukey Lewis of member station KQED - thank you, Sukey.

LEWIS: Thank you. Transcript provided by NPR, Copyright NPR.