Manhattan Criminal Court Judge Bonnie Wittner handed the sentenced down Monday against Rodney Alcala, 69, for killing Cornelia Crilley in 1971 and Ellen Hover in 1977.
Alcala pleaded guilty in December to killing Crilley and Hover, who were both 23 when they died.
He was convicted in 1980 and sentenced to death in California for killing two women in 1977. He won two appeals in the case but was eventually found guilty of the murders of four women and a 12-year-old girl, who were all killed between 1977 and 1979 in Los Angeles suburbs.
The judge in New York cried as she imposed the sentence Monday, CNN reported.
"This kind of case, I have never experienced, and I hope to never again," she said.
Alcala was nicknamed the "Dating Game Killer" because he appeared in 1978 on the TV show of the same name while he was carrying out a series of murders.