A Rochester drug dealer who sold a fatal dose to a confidential police informant fighting addiction pleaded guilty to murder Thursday and was sentenced to a term of slightly less than nine years.

Michelle A. Williams, 53, of Rochester, admitted to third-degree murder in connection with the death in late March of 32-year-old Matthew Klaus, who worked as an undercover informant for the Rochester Police Department.

Klaus, who had a long history with Rochester police and nearly died of an overdose in 2017, was paid by the department three times in March to buy purported heroin from Williams.

With credit for time in jail since her arrest, Williams will serve roughly the first 5⅔ years in prison and the balance on supervised release.

Shortly before going undercover, Klaus was sentenced on Feb. 20 to three years’ probation for driving after his license had been canceled.

On March 13, he made his first controlled buy from Williams under police guidance. He then made buys on March 19 and 21, turning over the purported heroin to police each time.

According to court documents, Williams told police she used heroin and sold it to Klaus for more than two years. She admitted selling tar heroin to Klaus at 11 a.m. on March 29. Police arrested her five days after Klaus was found dead March 30 in his Rochester home.

Klaus’ parents have said their son had recently completed 14 months of sobriety, and his death reignited the debate about the highly confidential practice of police employing people with criminal records as informants.

Asked during an interview this summer with the Star Tribune whether the benefits of informant work outweighed the risks in her son’s case, Denise Klaus replied, “No, not in our case. I mean, we lost Matthew … but we could’ve lost him even without him having been a — I don’t know. I don’t know.”


Star Tribune staff writer Chao Xiong contributed to this report.