The Opportunity Killer: How Scott Kimball Manipulated the FBI While Hunting His Victims
In the annals of American crime history, few cases illustrate the dangerous intersection of cunning and opportunity quite like that of Scott Kimball. Now serving a 70-year sentence in a Colorado federal prison, Kimball represents an unprecedented case of a serial killer who simultaneously operated as an FBI informant, manipulating the very system designed to catch predators like himself. Former FBI Special Agent Jonny Grusing, who spent 15 years pursuing Kimball, described the killer’s relationship with the Bureau in stark terms: “He made a game out of tricking the FBI. As long as he won the game in front of him, that’s all that mattered.” This disturbing case reveals not just the methodical mind of a serial killer, but the vulnerabilities within the criminal justice system that allowed him to operate in plain sight for years.
Kimball’s path to becoming both predator and informant began after a 2001 arrest for check fraud in Alaska. There, the then-37-year-old career fraudster identified an opportunity in his cellmate, Steve Ennis, who faced drug charges. With calculated precision, Kimball convinced Ennis that he had powerful connections who could make witnesses “disappear” and help with his case. Simultaneously, Kimball befriended Ennis’s girlfriend, Jennifer Marcum, a stripper working in Denver. After planting seeds of a potential murder-for-hire plot, Kimball reported to the FBI that Ennis was planning to have witnesses killed. This information earned Kimball confidential informant status, resulting in his transfer to a lower-security facility and eventual release. What the FBI didn’t realize was that they had just unleashed a predator who would use his protected status to hunt victims with virtual impunity. “To have someone who enjoyed manipulating us, putting stuff in our files, and then making people disappear was beyond anything I’d seen,” Grusing reflected, highlighting the unprecedented nature of Kimball’s deception.
By February 2003, Kimball was operating as a full-fledged FBI informant across the western United States, but Jennifer Marcum was already dead—one of his first victims while working for the Bureau. Marcum’s disappearance followed the January 2003 murder of LeAnn Emry, another stripper whom Kimball shot and abandoned in a remote desert area. His killing spree continued in August of that year with the disappearance of Kayci McLeod, and in 2004, Kimball murdered his own uncle, Terry Kimball. The serial killer’s audacity knew no bounds; he regularly provided “breadcrumbs” to the FBI that ended up in case files, including information that he was the last person seen with at least two of his victims. This perverse game of cat and mouse demonstrated Kimball’s psychological need for risk and validation. As Grusing noted, “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.'” In effect, Kimball was hiding in plain sight, using his relationship with the FBI as both cover and thrill.
It wasn’t until 2006 that the FBI began investigating their own informant, prompted not by internal suspicions but by pressure from victims’ family members. “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 Kayci was last with Scott, and that reporting was in the case file,” Grusing explained. This pivotal moment forced the Bureau to confront the possibility that they had been systematically manipulated by a killer operating under their protection. In March 2006, Kimball was arrested in California on fraud charges, giving the FBI time to build a murder case against him. By 2009, he was officially charged with four murders, though the true extent of his crimes remained unclear. Kimball would later confess to killing at least 21 people and, according to Grusing, told his own attorneys he was responsible for between 45 and 50 killings—a staggering number that, if true, would place him among America’s most prolific serial killers.
Even after his conviction, Kimball’s manipulation of the FBI continued as Grusing and other agents worked to locate the remains of his victims. “We knew he was manipulating us, pointing us in different directions, but he’s the only one who knew what happened to them,” Grusing said. “So even though it was painful to be in front of him and let him win all the time, as long as he thought he was squirming, he would always talk.” This painful dance between agent and killer persisted for years, eventually leading to the recovery of the remains of McLeod and Emry. During one of their many conversations, Kimball asked Grusing why he had never been given a nickname like other infamous serial killers. When asked what he would call himself, Kimball’s response was chillingly matter-of-fact: “The Opportunity Killer, because I just kill people when I have the opportunity.” This casual self-assessment reveals much about Kimball’s predatory mindset—he didn’t need elaborate fantasies or rituals; he simply needed vulnerability and access.
The Scott Kimball case stands as a sobering reminder of how systems designed to catch predators can sometimes enable them instead. His ability to manipulate the FBI while actively hunting and killing victims represents a perfect storm of cunning, opportunity, and institutional blind spots. For families like Jennifer Marcum’s, whose remains have never been found, the wounds remain painfully open. The legacy of “The Opportunity Killer” extends beyond his crimes to challenge law enforcement’s approach to informants and the safeguards needed when dealing with individuals who have demonstrated patterns of deception and violence. As Kimball serves out his 70-year sentence, his case continues to haunt both the FBI and the families of his victims—a stark reminder that sometimes the monsters law enforcement hunts are hiding within their own systems, manipulating from within while leaving a trail of devastation in their wake.
