John Floyd Thomas, 74, pleaded guilty to seven counts of first-degree murder and received seven life sentences, one without the possibility of parole.
He was arrested in 2009 and linked to the crimes by new DNA testing.
Investigators suspect he may be responsible for as many as 30 murders between 1975 and 1986.
During that time a man alleged to be Thomas entered the homes of middle-aged and elderly women in western Los Angeles County and raped and choked them.
