. >> this is prentiss place. you can see it's mostly vacant homes, back here. i believe this was the house right here. >> crystal and his colleagues chased after drug suspect antoine green and arrested him after he broke into this house to hide. >> i could hear the bang and the scuffle. it was obvious to anybody -- cop, person, 6 year old child, what went on at that point. >> what had happened? >> we found out later on from the trial, that green was assaulted while still in handcuffs, by officer williams. they take green out, his shirt is ripped, i noticed he was limping profusely. >> crystal reported the incident to a supervisor. >> he told me basically that if i snitched, my career was over. if i go to internal affairs, they're going to get me to rat and his exact words were "your career won't be worth [explitive]". >> then he went to the prosecutor's office, which eventually pressed charges. >> it's never right to take justice into your own hands. we're cops, you're supposed to uphold the law not take it into your own hands. once we start doing that we're no