Patrick was a thin boy growing up. This is enough to bring out the bullies, but to make matters worse, Kearney was also gay. This made him a prime target for the school's worst bullies when he was growing in the much more homophobic time of the 1960s. He was teased for being weak and effeminate. Some of the boys called him hateful slurs because of his sexual orientation.
When he was 13 years old, his father bought him a .22 caliber rifle so the two could go hunting animals together. In addition to hunting, his father taught him how to kill and slaughter pigs. But animals weren't the only thing Kearney fantasized about killing. While slaughtering the pigs, he'd often fantasize about killing the people who bullied him.
When he finished school, Patrick joined the Air Force. It was while serving in the military that he would meet the man who would become his on-again-off-again boyfriend, David Hill. At the time, David was married, but the two still began an affair. The relationship became more serious after Patrick was discharged from the Air Force. With Patrick free from military life, David left his wife so the two could move to California as a couple.
Living together proved difficult, and they began to argue frequently. Eventually, David had enough and decided to move back with his wife. This sent Patrick into a spiral. He became a regular at gay bars, where he would go on to meet many of his victims. Later, it would become a pattern that arguments with David set off his darker impulses. Hill returned once more and the two settled in together again. But the arguments continued.
Frequently, after having an argument with David, Patrick went on the hunt for someone to kill. Many times, these would be men he met at the gay bars. Other times, the victims were hitchhikers that he picked up alongside the road. Sometimes, his targets were just men who reminded Patrick of someone who bullied him as a child. However he found them, his routine was always the same. Patrick would get the person into his car and begin to drive to a secluded location. He always drove with one hand on the wheel, so he'd be able to shoot the victim with his right hand as soon as he was sure nobody would be around to see or hear the gunshot.
After killing the men and sexually assaulting their dead bodies, Kearney cut them into pieces with a hacksaw to dispose of the bodies. This was a change from his earlier killings as he refined his methodology. He'd then place the cut-up body parts in trash bags and dump them in various locations. He often chose a location near a freeway to make this dump. Because of these actions, Patrick would become known as "The Freeway Killer" or "The Trash Bag Killer."