PORTLAND – The cold case investigation of a murder 22 years ago yielded Friday an arrest in New Hampshire of a 60-year-old “street person” accused in the strangulation of a Portland woman.

The suspect, Roger Bernier, was the last person known to have seen Mary Kelley alive before her body was found on April 26, 1986, in the bathtub of her Congress Street apartment, police said.

Bernier was arrested at his Manchester, N.H., apartment after he was named in a murder indictment returned by the Cumberland County grand jury.

Investigators said forensic evidence scrutinized with updated analysis methods along with new information gleaned from interviews over the past two years led detectives to Bernier, who had been interviewed at the start of the investigation and at various times thereafter.

Portland Police Chief Timothy Burton would not go into specifics about the evidence that enabled his department to crack the case, nor would he comment on a motive for the killing.

Bernier, who has no criminal record, was being held in Manchester as a fugitive from justice and will be returned to Portland immediately if he elects to waive extradition Monday, police said.

The investigation, involving generations of detectives, included interviews with more than 40 people, many of whom were questioned repeatedly. Bernier had told police that he left Kelley’s apartment on the night of April 25 after she said she was going to take a shower.

Detective Karl Rybeck, part of a team of detectives that took a fresh look at the case two years ago, described Kelley and Bernier as acquaintances who were not involved in any relationship.

“He was just a guy from the street she knew. She was, for lack of a better term, a street person herself,” Rybeck said. Kelley, 33, knew many people from the neighborhood and often allowed them into her first-floor apartment at the Lafayette Townhouse.

Bernier was born in Germany, moved to the U.S. as a child and attended high school in Biddeford, police said. He spent 10 years in the military, which included a tour in Vietnam, and moved to Portland in 1982. Five years later, he moved to Portsmouth, N.H.

Burton credited the unwavering support given to investigators by Kelley’s daughter, Myana Escamilla, for helping his department crack the case.

Escamilla was 7 and was staying with her grandmother in the Boothbay area at the time of the slaying. Now 30 and living in California, she has remained in touch with detectives over the years and recently graduated from law school.

Three years ago, Escamilla announced a $5,000 reward for information leading to the arrest and conviction of her mother’s killer. Burton said he did not believe that anyone would be eligible to claim the money.

Noting that homicide cases remain open forever, Burton said Portland has six other unsolved killings and he hopes Friday’s arrest will offer hope to families of the other victims.

“We never give up on homicide cases. We never give up. This has been 22 years and this man is under arrest,” the chief said.