HILO, Hawai'i — Convicted killer Frank Janto has pleaded guilty to a second murder in the slaying of an elderly woman in Hilo in 1987.

Janto entered the plea before Hilo Circuit Judge Greg Nakamura on Friday. He faces a mandatory sentence of life in prison with the possibility of parole for the murder of 65-year-old Rose Chiquita. Janto's sentencing is scheduled for Jan. 7.

Deputy Prosecutor Rick Damerville said the Chiquita case was solved after investigators familiar with the highly publicized murder of Bongak "Jackie" Koja in Wahiawa in 1997 noted similarities between that case and the Chiquita killing, and urged police to consider Janto as a possible suspect in the Hilo killing.

Police were then able to build a case from DNA evidence that tied Janto, who lived in Hilo for years, to the sexual assault and slaying of Chiquita.

Chiquita regularly walked from the Hilo elderly housing complex where she lived to collect cans around her neighborhood in the mornings, Damerville said. A custodian found Chiquita's body lying on a bathroom floor at a gas station on Kino'ole Street in Hilo, about 200 yards from her home on the afternoon of Jan. 15, 1987.

An autopsy determined that she died of wounds to her head and body.

Koja, 59, was on her regular early morning walk on June 9, 1997, when Janto attacked and killed her at Leilehua High School. Janto told police that he had been smoking crystal methamphetamine and cocaine before confronting Koja, and admitted striking Koja and pounding her head on the pavement on the high school grounds.

Nearby residents apparently mistook a five-minute-long series of screams they heard the morning of Koja's death for rowdy teenagers.

During that investigation, Honolulu detectives learned Janto had dragged Koja's body to the back of the school and put her in a trash bin. Later that day, the trash bin was taken to the H-Power plant in Campbell Industrial Park, and Koja's remains were never recovered.

Janto was identified from a handprint in Koja's blood that he left on the side of a trash bin, Damerville said. The state Paroling Authority set a minimum term of 75 years in prison for Janto for the Koja murder before he can be eligible for release.

Police said the investigation into the Chiquita murder stalled until Honolulu police investigating the Koja murder realized Janto had lived on the Big Island, and noticed similarities in the two killings. That information was forwarded to Big Island police in 1998.

The case against Janto for the Chiquita slaying was submitted to Big Island prosecutors in 2001, and Janto was indicted early this year.

"Some people think they're cold cases, but the Hawai'i County Police Department kept after this case for years," Damerville said.

Janto also was convicted in yet another attack on an elderly woman in Honolulu, and served prison time in that case for second-degree assault, Damerville said. In that case, Damerville said, the woman jumped into the Ala Wai Canal to escape from Janto.

Janto also was sentenced to 10 years in prison for sexually assaulting a 9-year-old girl, and was released in 1996 after serving the full 10-year sentence in that case.