The Hillside Strangler, later the Hillside Stranglers, were two American serial killers who killed ten young females in Los Angeles between October 1977 and February 1978.
It was thought at first that only one person did the killings. The police, however, knew from the positions of the dead bodies that two individuals were working together. These two individuals were eventually discovered: they were cousins Kenneth Bianchi and Angelo Buono Jr.. They were later convicted of kidnapping, raping, torturing and murdering ten females, who were from 12 to 28 years old.
A big investigation had been fruitless. Then the arrest of Bianchi in January 1979 for the murder of two more young women in Washington was linked to his past in the Strangler case.