Kudos to the creative side for taking a look at this from the side of the female members of the Manson Family. As others have said it was just a little slow and didn't seem to get the most out of a pretty good cast. I don't think the film seeks to absolve the females of their guilt. I think they just tried to take an honest look at how vulnerable people can get indoctrinated. I would also disagree with those who call this a feminist movie, the movie does not seem to have any agenda just looks at these tragic murders from a different perspective. There is some nudity and sexuality which I think is necessary to accurately reflect the nature of the Manson Family Cult. As others have said, the movie is split between the flow of events in 68-69 and jail interviews after the trials. The jail scenes IMO are the best. The scenes at the ranches are a bit dark and tedious at times. There is one odd historical inaccuracy listed below.
WARNING ONE SPOILER: In the film, Manson accidentally meets Sharon Tate then immediately sends the family out to kill her. This accidental meeting did take place but was several months before the murders.