Authorities in western Michigan are looking into missing persons cases and unsolved homicides after interviewing a convicted murderer and long-haul truck driver with terminal cancer who died last week in a prison hospital.

Kent County sheriff's detectives questioned Garry Artman on three occasions before his death Thursday at a state Corrections health facility in Jackson, Michigan. In a statement to CBS News, Kent County Lt. Eric Brunner said officers were working "to determine if Mr. Artman can be tied to any other homicide or missing person cases."

Brunner said detectives "gleaned information" from their interviews with Artman and are collaborating with other law enforcement agencies to "connect the dots with missing pieces or homicide cases that are still open."

Brunner would not say which unsolved cases are being looked into or how many cases are being investigated, although police in Grand Rapids, Michigan, have tied Artman to a woman's disappearance nearly 30 years ago.

"Interviews with Artman provided enough information to reasonably conclude he was involved in the 1995 disappearance of Cathleen Dennis but that it is very unlikely that Dennis' body will ever be found," a Grand Rapids police spokeswoman said Wednesday.

Grand Rapids detectives also met with Artman before his death and are trying to determine if he is connected to other missing persons or homicide cases in that city, the spokeswoman said in an email.

WOOD-TV first reported Artman was being investigated in other cases. Sources told the station that Artman confessed to nine murders for which he never faced charges.

"Other information from WOODTV8 here in Grand Rapids was obtained through their non-law enforcement sources," the Kent County Sheriff's Office told CBS News in a statement.

John Pyrski, Artman's court-appointed lawyer, told The Associated Press Wednesday that he didn't know if Artman had committed other murders. But "if he did, I'm glad he made everything right in the end" by disclosing them, Pyrski added.

Artman, 66, had been diagnosed with terminal lung cancer. A Michigan jury in September convicted him of the 1996 rape and murder of Sharon Hammack, 29, in Kent County. He was sentenced in October to life in prison without parole.

Artman also faced murder charges in the 2006 slaying of Dusty Shuck, 24, in Maryland. Shuck was from Silver City, New Mexico. Her body was found near a truck stop along an interstate outside New Market, Maryland.

Artman, who had been living in White Springs, Florida, was arrested in 2022 in Mississippi after Kent County investigators identified him as a suspect in Hammack's slaying through DNA analyzed by a forensic genetic genealogist.

His DNA also matched DNA in Shuck's slaying.

Kent County sheriff's investigators later searched a storage unit in Florida believed to belong to Artman and found several pieces of women's underwear that were seized for biological evidence to determine whether there were other victims, Maryland State Police said in a 2022 news release.

Investigators from the Maryland State Police Homicide Unit traveled to Michigan to conduct interviews and gather additional information relevant to the investigation, CBS Baltimore reported at the time. 

Artman previously served about a decade in Michigan prisons following convictions for criminal sexual conduct in 1981.

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• Murder
• Michigan