Huh, now I’m really sure we watched a documentary about the Manson murders when I was in high school (early '90s), but I have no idea why, or even what class it would have been in.
Until I read her obit I didn’t realize she actually didn’t take part in the murders (she acted as look out), and co-operated with police against the rest of the “family”. I assumed based on her infamy in popular culture (including the band named after her, who did start sucking after their first couple of albums, but that’s hardly her fault 
) I assumed she was a central part of their crimes.
Even is she had run to a neighboring house, it wouldve been too late to save the victims.