Forty years after he was convicted for his involvement in two murders committed by Charles Manson, a California parole board has found that Bruce Davis is suitable for parole. His crimes, if it matters (and why should it?), didn’t involve the notorious murder of the pregnant Sharon Tate; he participated in the killing of a musician and a stuntman. Early on, Davis claimed he was simply a bystander. A jury didn’t agree. Since then, he has acknowledged shared responsibility. He has also been a model prisoner. He became a born-again Christian. He earned a master’s degree and a doctorate in the philosophy of religion. He ministered to other prisoners.

Is that enough?

If the purpose of prison is to rehabilitate or incapacitate dangerous offenders for our protection, then Davis is a safe bet. The grainy picture of him today bares no resemblance whatsoever to the scary-looking guy from 40 years ago. Arrest rates for those 65 and older top out at around 2 percent. Recidivism rates are the lowest for older offenders.