In February of 2007, a man (later to be revealed as Jerry Jacks) held the Metro Court Hotel hostage while he and his team of masked gunmen tried to retrieve a briefcase from the hotel vault. All the gunmen were called by numbers, with the ringleader being called Number One. The hotel desk clerk, Sam McCall, activated the silent alarm. When she did this, it automatically alerted the PCPD and locked the vault for a twelve hour period. The gunman called Number Three, later revealed as Coop, had taken a hostage, Maxie Jones, into the vault for the briefcase, thus being stuck in there together for the twelve hours. While in the vault, Maxie and Three talked and bonded. They got to know each other and started to care for one another. At one point, Maxie removed Three's mask, and when the vault was finally opened, Maxie helped him escape.
Maxie encouraged Coop to stay in Port Charles and put in a good word for him with the Metro Court Hotel owner Jasper Jacks for him to get a job as a hotel security guard. Max Giambetti, however, was the head of security and had a nagging suspicion that he recognized Coop from somewhere. When Coop stopped a purse snatching, it occurred to Max where he had seen him and had Stan Johnson look into Coop's background.
Knowing the truth about Coop, Max told his real boss, Sonny Corinthos, who decided to use Coop to his advantage. He blackmailed Coop into joining the PCPD as a police cadet. He used Coop as an insider in the police department to feed him information.
In late 2007 and early 2008, a serial killer, known as the Text Message Killer, terrorized Port Charles. Maxie's sister Georgie Jones became suspicious that the killer might be Coop. Georgie had Damian Spinelli check out Coop's background. In his search, he found that Coop was a military veteran and that a woman had been raped an strangled to death in the Iraq town where he served, and Coop had been a suspect. The women whom the Text Message Killer had murdered, had been strangled too, so this information made it look as though Coop might be the killer.
Then, Georgie herself was murdered--strangled to death. In the police investigation of her murder, they found DNA from Coop's skin underneath Georgie's fingernails. The police were closing in on Coop, so he stole the DNA results from the PCPD and asked Maxie to leave town with him, which she agreed to. When Maxie got to Coop's room at Kelly's though, she found him hanged to death. The PCPD ruled it a suicide, but Maxie wasn't convinced. She did not believe Coop killed himself, nor Georgie. The true identity of the Text Message Killer was later revealed to be Diego Alcazar, who had killed Coop as well because he thought he was getting close to figuring out his identity. Coop, however, had actually suspected Lorenzo Alcazar, though, not Diego.