A native of Holmen, Wisconsin, born in 1960, Tenneson was serving felony time in the La Crosse County jail when he failed to return from a work-release outing on March 10, 1987. Ten days later, still in La Crosse, he invaded the home of 73-year-old Lila Bush, shooting her to death, along with her 33-year-old son Kenneth and Kenneth's 35-year-old girlfriend, Debra Reget. On March 21, traveling as "Michael Leith," Tenneson stepped off a bus in Denver, passing two months in the Rocky Mountain metropolis before he felt the urge to kill again. On May 20, following a beer and cocaine party, he turned on two new friends -- 23-year-old Jeffrey Sheffield and 22-year-old Mitchell Gonzalez -- shooting both men in the head, at point-blank range, while they slept off the affects of drugs and alcohol. Showing off Sheffield's car the next evening, Tenneson quickly fell under suspicion and was jailed on murder charges. While in custody, he voluntarily confessed to the Wisconsin slayings. On March 18, 1988, a Denver jury convicted Tenneson on two counts of murder, plus one count each of aggravated robbery and aggravated auto theft. A week later, deadlocked eleven-to-one in favor of execution, jurors were forced to recommend life imprisonment in the absence of a unanimous verdict. Tenneson was sentenced to matching life terms for the murders, plus 32 years on the robbery count and 16 years for auto theft, compelling him to serve a minimum of 104 years before he is eligible for parole. On June 14, 1988, Tenneson was returned to Wisconsin for trial on triple murder charges and assorted other felonies. He struck a bargain with authorities, against the best advice of his attorneys, telling the court, "It's ridiculous to go through all this." In return for his guilty plea on three counts of murder, he was sentenced to three more life terms, with dismissal of lesser charges including armed burglary, possession of a firearm after conviction of a felony, and violation of the state's repeat offender statute.