In a plea bargain, Kimball pleaded guilty in 2009 to two counts of second-degree murder in the deaths of Jennifer Marcum, Kaysi McLeod, LeAnn Emry and his uncle, Terry Kimball. The slayings happened in 2003 and 2004, after Scott Kimball was released from prison to become a paid FBI informant.

Despite the guilty plea, for years Kimball tried to blame others in some of the cases until this letter.

The newspaper said Kimball admits he was responsible for the death of Kaysi McLeod, 19, of Westminster, and disposed of her remains, though he did not plan for her to die. Kimball reportedly wrote that he was the only person present when McLeod overdosed on alcohol, methamphetamine and OxyContin that he gave her.

Kimball also confessed to killing Jennifer Marcum, 25, by giving her an overdose of heroin in a Utah canyon in 2003, the newspaper reported. Her body has not been found.

Kimball also admitted killing his uncle and LeAnn Emry, who he shot twice in the back of the neck when she tried to escape him in Utah, according to the letter.