Updated

NEW YORK -- A convicted 1970s serial killer on California's death row is being charged with the decades-old killings of two women in New York, a law enforcement official said Thursday.

Rodney Alcala has been indicted on murder charges in the 1970s deaths of Cornelia Crilley and Ellen Hover, slayings that had been relegated to cold-case files years ago but were re-examined in the wake of his conviction last year, the official said.

Crilley, a flight attendant, was found strangled in her Manhattan apartment in 1971. Hover disappeared in 1977; her remains were later found on an estate outside the city.

The official spoke on condition of anonymity to discuss an indictment that has not been made public. The Manhattan district attorney's office declined to comment but had a news conference scheduled Thursday afternoon.

Alcala, 67, was found guilty last year of strangling four women and a 12-year-old girl in California in the 1970s. After the verdict, authorities released more than 100 photos of young women and girls found in the amateur photographer's storage locker, and prosecutors said authorities were exploring the possibility of tying Alcala to cases in other states including New York.

Alcala remained in prison in California on Thursday, though authorities planned to start taking steps to bring him to New York, the official said. He represented himself in his California case, and it wasn't immediately clear whether he would have an attorney in New York.

Alcala had been a suspect for some time in Crilley's and Hover's deaths, but a cold-case unit established last year in the Manhattan DA's office was able to build on the California case and other evidence to obtain an indictment, the official said.

It wasn't immediately clear how Alcala might have known Crilley and Hover.

Alcala had been convicted and sentenced to death twice before in the California girl's 1979 murder, but the verdicts had been overturned on appeal. Drawing on DNA samples and other evidence, prosecutors refiled charges in her death and added the four other murder charges in 2006.

His trial was both gruesome and bizarre. Prosecutors portrayed him as a killer with a penchant for torturing his victims, raping one with a claw-toothed hammer and posing several victims nude in sexual positions after their deaths.

Alcala, acting as his own attorney, offered a rambling defense that included questioning the mother of one of his victims, playing Arlo Guthrie's 1967 song "Alice's Restaurant" and showing a TV clip of himself on a 1978 episode of "The Dating Game."