Part 5: There's one important part of the newspaper's story we couldn't bring you until now: what it's like to have their attacker stand trial. And the unexpected ways that trial can affect you. Plus a big update about the newspaper itself.

One of the first police shootings to be captured on cell phone, millions saw Bay Area Rapid Transit police Officer Johannes Mehserle fire a single, fatal gunshot into Oscar Grant's back as the 22-year-old lay face down on the train station platform. Now, a lawsuit filed by NPR member station KQED has forced BART to comply with California's 2019 police transparency law, and release never-before-heard tapes from inside that investigation.

Fellow officers long suspected a veteran detective in Antioch, Calif., was leaking operational police secrets to a drug dealer. For years, the department didn't act on their concerns. Even after the detective was finally fired in 2017, his record remained secret. In episode six of On Our Watch we look at the incentives departments have to investigate dishonest cops and what the secrecy around police misconduct means for criminal defendants who are prosecuted on their testimony.

An officer is repeatedly disciplined for not turning in his police reports on time. A mom goes to the police asking for help with her missing daughters. In the fifth episode of On Our Watch, we look at what can happen when police don't follow through on reports of victimization, and an accountability process that doesn't want to examine those failures.

A 16-year-old Black kid walks into a gas station in Stockton, Calif. to buy gummy worms for his little sister. When the teen gets in an argument with the clerk over a damaged dollar bill, a white officer in plainclothes decides to intervene — with force. In the fourth episode of On Our Watch, we trace the ripple effects of this incident over the next 10 years in a department trying to address racism and bias. But can the chief's efforts at truth and reconciliation work when the accountability process seems to ignore the truth?