|Japanese Name||Zaimon Kyousuke|
|Family||Brother: Neil Marshall|
Two years prior to the case, Jake was working as a detective and was assigned to the SL-9 case alongside fellow detectives Angel Starr, Bruce Goodman, Lana Skye, Damon Gant and his brother, Neil Marshall, who was the prosecutor assigned to the case. For 6 months they pursued Joe Darke, a serial killer, but were unable to arrest him at first due to a lack of evidence linking him to the crimes. Whilst Darke was in police custody he escaped and took Ema Skye, Lana's younger sister, hostage, he was chased down by Neil and he became Darke's 6th victim. In the process Darke had left evidence for the first time so he was finally convicted and executed. But something felt off about the whole thing to Jake as he knew he brother was a capable fighter, and, shortly after the case, it became apparent that falsified evidence had been used during the trial. As a result Angel was fired and Jake was demoted to patrolman.
He was stationed as a security guard to the police department evidence room, although the room mostly took care of itself as due to it's advanced security system. Two years passed since the SL-9 case was closed and Jake, along with Angel, continued to investigate the case on the side, but the day of the evidence transferral arrived and the case would be closed forever. Jake approached Goodman, as he was the head detective in charge of the case, and asked him to re-open it. Goodman refused so Jake stole his ID card and disguised himself as Goodman to gain access to the evidence room. Once inside he went to the locker to steal the evidence when he was interrupted by Mike Meekins. Jake panicked after being discovered and knocked him out, fleeing the evidence room. After his presence in the room had been discovered later on, he was brought in for questioning, aiding the case despite the reason he was in there had gotten him fired. As the trial closed, everyone learnt that Jake's hunch had been right, and Neil was actually murdered by Damon Gant.