lester holt: district attorney larry krasner says the tony wright case is hardly unique.viction integrity unit has helped free 28 people, all victims of official misconduct. his office is investigating dozens of other cases. you're looking at the actions of the prosecutor, or the police? larry krasner: both. the biggest part of this problem is not just innocent mistakes. the biggest part of this problem is the abuse of power. lester holt: in february 2020, krasner's office, together with defense attorneys, did something rarely seen. they filed a joint motion, asking the court to vacate ogrod's conviction. tom lowenstein: it's unbelievable. they came up with 160 stipulations with the defense of things that had gone wrong. lester holt: for nearly 30 years, sharon fahy hated ogrod. but after meeting with prosecutors from the conviction integrity unit, she became furious with the people who put him away, and heartsick for the man she now believes is innocent. this is a man you wanted to die, and now you're saying you want him free. yes. once i had all the facts, i, in my hear