A man arrested in Minnesota this week in relation to a 25-year-old Pennsylvania killing was a homeless drifter, authorities in Pennsylvania said in a news conference Friday.

Charles Cook, 61, had been called a resident of the southwestern Minnesota town of Magnolia several years after a 2007 DNA test linked him to a cigarette butt found in a car believed to be stolen from the victim and later abandoned.

Cook has been charged with criminal homicide in the death of 76-year-old Myrtle McGill, who was killed in her kitchen in Pennsylvania's Indiana County in early December 1991.

The Indiana Gazette reported that McGill was hit by two .22-caliber bullets fired through her kitchen window. Her body wasn't discovered for days. Someone had smashed the sliding glass door to get into the home, the paper reported, but the only thing taken from McGill's home was her old Ford sedan. Days later, it was recovered at a Greyhound bus station near Pittsburgh. Her body was found several days after that, on Dec. 13.

Pennsylvania authorities said in a Friday news conference streamed live on Facebook that they believe the killing was random. Cook had absconded from parole in December 1991 after being imprisoned in Pennsylvania on drug charges, authorities said.

He was supposed to report to a residence in Philadelphia but instead boarded a bus and ended up passing through Indiana County.

New DNA technology led authorities to test the cigarette butt they had collected from McGill's car so many years earlier.

Cook was convicted of crimes in 1998 and 1999 in Washington state and identified as a sex offender who was required to provide his DNA to a law enforcement database.

Pennsylvania authorities extradited him back to their state in 2000 to serve the remainder of his sentence, on which he was paroled a second time in June 2004. After that, Cook was transient, authorities said, living in Ohio, Illinois, California, North Dakota and multiple locations in Minnesota.

He was last registered as an adult sex offender and sexual predator in Illinois, listing his address as "out of state, Magnolia, MN," according to Pennsylvania authorities.

Cook was arrested and released last December in Worthington, Minn., and was reported to be homeless, living in a disabled motor home.

Pennsylvania authorities found him in Minnesota in March of this year and interviewed him, getting another DNA sample in the process. They learned that soon after that he was arrested again, they said.

It took a while for authorities to track Cook down, they said. They also wanted to confirm that he was in Pennsylvania at the time of the killing.

"DNA, in and of itself, it's a great tool but it's only one piece of the puzzle," Indiana County District Attorney Patrick Dougherty said. "We wanted to try to put him here."

Cook is now in custody in Minnesota on unrelated assault charges, Pennsylvania authorities said, though they didn't have details. They are working to extradite him to Pennsylvania for the homicide case.

Minnesota court documents list a 61-year-old Charles Cook as having been arrested on assault and other charges in March in Blue Earth County for threats involving motorists while he was panhandling. Both states list his name with the same aliases but with slightly different dates of birth. In Blue Earth County District Court, Cook was found incompetent to proceed to trial and was civilly committed as mentally ill, pending his restoration to competency.

Pennsylvania authorities announced earlier this week that they had arrested a 61-year-old resident of Magnolia in connection with the killing, but they wouldn't give details, including the name of the person arrested. The news left people in Magnolia, with a population of about 200, in suspense, unsure who among them might be considered a killer.

Rock County Sheriff Sgt. Jeff Wieneke said Friday that Cook had spent some time at a campground in Magnolia in 2015.

"To be honest with you, I don't know why they're claiming a Magnolia, Minnesota, address for him," Wieneke said.

Pam Louwagie • 612-673-7102