Tate, the wife of director Roman Polanski, was 8 1/2 months pregnant when she was killed with 16 knife thrusts by cult members at her hilltop home on August 9, 1969.
Coffee heiress Abigail Folger and three others were stabbed and shot to death at Tate's home in the frenzied attack. The word "Pig" was written on the front door in blood.
The next night, two others were stabbed to death at their homes. "Death to pigs" was written on a wall, and "Helter Skelter" on the fridge door.
The cult leader was first sentenced to death for conspiring to murder seven people.
Manson's co-defendants -- "family" members Susan Atkins, Leslie Van Houten, Patricia Krenwinkel and Charles "Tex" Watson -- were convicted with him. But their death sentences were commuted to life when the death penalty was briefly outlawed in the US in 1972.
Manson was also convicted of the earlier murder of musician Gary Hinman in his Topanga Canyon home, and the slaying of former stuntman Donald "Shorty" Shea at the Spahn movie ranch in Chatsworth, where Manson had his commune.
The septuagenarian has made 11 failed bids for parole since 1978, the last in 2007 when he was ordered to continue serving life sentences. Manson's next parole hearing is scheduled for 2012.
Last year, Susan Atkins, dying of brain cancer, failed to win parole on compassionate grounds.