They both became dependent on drugs and drinking.
Both Pallenberg and Jagger were members of the cast.
Anita cut Brian's hair, dyed it to match her own, and wore the same clothing styles.
As reported by Rolling Stone, he said that he couldn't believe that a girl like Anita was with Brian.
The longtime couple, never married, had drifted apart by 1979 when Pallenberg became close with Scott Cantrell, the 17-year-old groundskeeper of the home she had shared with Richards in South Salem, New York.
A cause of death has yet to be determined.