Cold Case (2003) - 1x07 - A Time to Hate

Lilly investigates the case of Daniel Holtz, a college baseball player who was found beaten to death in an alley behind a gay bar in 1964. Daniel's mother comes to Lilly in the hope that his killer can be brought to justice before she dies. Lilly discovers the maltreatment gay victims received in the 60's, when her investigation discloses that it may have been a policeman's nightstick that made the lethal blows.