LEWISTON – Human remains that were found in a freezer in a storage unit this fall were those of a former girlfriend of the man who rented the unit for nearly 20 years, law enforcement officials said Friday.

Because of decomposition, tissue samples from the body had to be sent to a Pennsylvania laboratory, which used DNA from the remains and a relative’s DNA sample to confirm the identity of Kitty Wardwell, said Steve McCausland, spokesman for the Maine Department of Public Safety.

The state Medical Examiner’s Office determined that Wardwell’s death was a homicide, but the cause of her death was being withheld Friday.

“We’re in the initial stages of this investigation. At this point, withholding the cause of death is appropriate as we try to get further answers,” McCausland said.

The storage unit was rented by Wardwell’s former boyfriend Frank Julian, who died Oct. 1 at the age of 80. Wardwell had been missing for 28 years.

Dwight Collins, Wardwell’s older brother, said the family believed from the beginning that Julian had something to do with her disappearance.

“We’re relieved that we finally have closure on it,” Collins said from his home in Bucksport. “We know it’s her. We can put her to rest now.”

Julian declined to take a polygraph test while discussing Wardwell’s disappearance and didn’t seem interested in what had happened to her, a retired Maine State Police investigator told The Associated Press in late October.

Joe Zamboni said Julian’s story about going with Wardwell to Salem, N.H., having a fight with her and leaving her at a motel didn’t seem plausible to investigators because it seemed unlikely she would leave without contacting family members. But it was difficult to advance the investigation because there was no body and no crime scene, he said.

The remains were discovered in October by Julian’s family members as they cleaned out the 10- by 10-foot storage unit. The storage company’s owner said Julian had paid for the unit in advance every three months since 1992. The body was in an unplugged freezer, a floor model with a door that opened on the top.

There is a nine-year gap between the time Wardwell disappeared and the time Julian rented the locker, so investigators have many questions, including where she died and where her body was before it was put in the storage unit, officials said.