Joseph Drake, 21, faces a hearing Wednesday after three people, who live in "cubby holes" under urban railroad tracks, told police paintballs were fired at them from overpasses.
Drake and two other men were seen firing at the victims, and Drake was captured Thursday nearby allegedly in possession of paintball guns, police said.
The police report mentioned the two other men "convinced him to go down to the train tracks to shoot paintballs at bums" and that "his brother was killed by a homeless person 10 years ago and he hates how they beg for change and harass him."
His older brother, Scott Drake, was 11 when he was strangled and sexually mutilated in 2000 by a homeless man, Joseph Cornelius, who confessed to the crime and is currently in prison, the Pittsburgh Post-Gazette reported Tuesday.
Joseph Drake will be charged with felony aggravated assault and other charges while the search for the other gunman will continue, Lt. Christopher Ragland of Pittsburgh Police Zone 1 Station said.