Scott Lee Kimball was born on September 21, 1966, in Boulder, Colorado. His early life took a difficult turn when, at the age of 10, his mother, Barb, came out as a lesbian. This revelation led to his parents' divorce, and his father, Virgil, left the state and remarried. Scott was greatly affected by the divorce.

During his early teenage years, he had his first encounter with law enforcement. Police were called to his home after he fired a gun out the window at neighboring houses. After this incident, Scott and his younger brother Brett sought refuge with their grandmother, living in her mobile home. Unfortunately, a neighbor named Theodore Peyton began sexually abusing both boys at a cabin he owned in Nederland, Colorado. The abuse escalated over time, resulting in traumatic experiences for Scott.

When Scott moved to Hamilton, Montana, to live with his father and brother, he continued to face abuse during visits back to Boulder on weekends. The abuse only ended when Scott was 23. At that time, he attempted suicide by shooting himself in the head. The bullet glanced off his skull, leaving a serious injury that required critical care for several days. After this traumatic event, Scott, along with other victims, reported Peyton to the police. Peyton was later arrested and convicted of multiple counts of sexual assault.

Scott grappled with feelings of shame and inadequacy due to the abuse he suffered. He even wrote a letter to the judge asking for a severe sentence for Peyton, expressing how the abuse had destroyed his childhood. Years later, when asked about the incidents, Peyton responded that it was a long time ago, further highlighting the lasting impact on Scott’s life.

Scott Lee Kimball was involved in a number of murders over a relatively short period. Between 2003 and 2004, he confessed to killing at least four people. Three of these murders occurred while he was working as an informant for the FBI.

One of his victims was Jennifer Marcum. After his release from prison, Kimball met Marcum, who was tied to individuals he had connections with. He convinced her to move in with him as part of an alleged plan to help her career. She soon disappeared after transferring her belongings to Kimball's home. Shortly after, Kimball mentioned to an FBI agent that he heard she was dead, but he provided no details.

Another victim, LeAnn Emry, was involved in criminal activities with Kimball. Emry was last known to have traveled with Kimball under the pretense of going caving. Instead, they committed various thefts across several states. Her body was later found in a remote area in March 2009.

Kaysi McLeod, the daughter of Kimball’s third wife, also went missing around this time. Kimball told several conflicting stories about her disappearance, but no solid leads were found for years. Eventually, McLeod's remains were located in Routt National Forest.

Scott Kimball also killed his uncle, Terry Kimball. After his uncle's disappearance, financial irregularities linked to him became apparent. Terry’s body was discovered in 2009, after years of being missing.

During his time as an FBI informant, Kimball was able to mislead authorities while continuing his criminal activities. His pattern of deception and manipulation enabled him to carry out these killings without immediate detection.