FBI informant revealed to be serial killer who tricked feds, murdered up to 50 people: former agent

A former FBI agent has said that a convicted serial killer who doubled as an FBI agent was able to manipulate other agents into helping him while he was preying on victims.

Scott Kimball was sentenced to 70 years in prison in 2009, and will likely spend the rest of his life behind bars. He pleaded guilty to the murder of four people between 2003 and 2004. According to former FBI agent Special Agent Jonny Grusing, that number could be much higher.

"He made a game out of tricking the FBI," Grusing told Fox News. "As long as he won the game in front of him, that’s all that mattered. To have someone who enjoyed manipulating us, putting stuff in our files, and then making people disappear was beyond anything I’d seen."

Kimball, who is now 58, spent time in and out of prison in the 1990s and was known as a serial fraudster. He then practiced working the criminal justice system to his benefit, becoming an informant for the police as well as blaming his cellmate for crimes. To get his way into being an FBI informant, Kimball convinced his cellmate Steve Ennis that he had powerful connections and that witnesses in Ennis' drug case could be "taken care of." He also befriended Ennis' girlfriend Jennifer Marcum, who was a stripper at the time.

After Kimball was able to plant the seeds of a murder plot, Kimball reported the plan to the FBI. Kimball was then moved out to a lower security prison and released. "Our primary victim in our case was Jennifer Marcum," Grusing said. "Mainly, he convinced Steve [Ennis] to hook him up with Jennifer to get Jennifer out of stripping. So, at the same time he's making Steve look like the bad guy, he's taking Jennifer and isolating her and killing her."

Kimball became a full-fledged FBI informant by 2003. From 2003 to 2004, Kimball was responsible for the deaths of four people. Kimball confessed to killing 21 others, but Grusing said that there were as many as 45-50 killings he was responsible for. Other alleged victims have not been named.

In addition to killing Marcum, Kimball was discovered to have killed LeAnn Emry, who was another stripper. She was shot and left for dead in the desert one month before Marcum's murder. Kaysi McLeod also went missing that year in August. Kimball eventually confessed to the murder. Additionally, in 2004, Kimball killed his own uncle, Terry Kimball.

Only in 2006 was the FBI pressured to investigate its own informant. Along the way, he had left "breadcrumbs" on the FBI files on each of the cases.

"And that's when two dads came to the FBI office to talk to my boss and say, not only was Scott responsible for Jennifer's disappearance, but another girl named Kaysi was last with Scott, and that reporting was in the case file," said Grusing. "But Scott had mastered such that, again, he enjoyed the game, and it was like leaving little breadcrumbs to say, 'I'm so good at this, I can tell you about these homicides, and you'll never know I'm doing them.'"

He was officially charged with the murders in 2009 and later convicted.