Jerry Collins was a detective for the Los Angeles Police Department who was assigned on the krugerrand case.
He was seen at the station while Riggs was placing a bet that he could free himself out of a straightjacket that he's in. After Riggs frees himself, Collins and the other detectives put their money on the table for Riggs.
The next day, after the attack on Murtaugh at his house by Vordstedt, Collins and the others go with Riggs and Murtaugh at Rudd and Vorstedt's stilthouse and arrest them all there. The arrest doesn't go as planned because they revealed themselves to be diplomats, and thereby could not be arrested, tried, convicted, or even prosecuted.
Collins was seen the next day at Cavanaugh's house playing poker with Cavanaugh, Moss and Friesen when all the sudden, when Cavanaugh was about put on some music, a bomb, planted in the stereo by Vordstedt or one of his men, explodes the entire house, killing them all, including Collins.