Alcala pleaded guilty to the murders of Cornelia Crilley and Ellen Hover in the 1970s. Crilley, 23, was found strangled with a stocking in her Manhattan apartment in 1971. Hover, also 23, was living in Manhattan when she vanished in 1977. Her remains were found the next year in the woods on a suburban estate.
Emotions ran high when the victims' families spoke during the sentencing. Even Judge Bonnie Whittner was seen choking back tears as she sentenced Alcala to 25 years to life.
"This kind of case is something I've never experienced - hope to never again," Whittner said. When she finished pronouncing the sentence, she put her head in her hand.
Alcala is already on death row in California for five killings. He said last month that he pleaded guilty in New York so he could return to California and appeal his death sentence. He had complained that his jailers in New York wouldn't give him access to a laptop computer and legal records.
The Associated Press contributed to this report.