Since the US has more people in prison than any other country, shouldn’t we be working on an effective method of rehabilitation? A potential solution comes from an unlikely place, the notorious Donaldson Correctional Facility in Alabama, where the resident psychologist brought in a pair of teachers to instruct volunteers in Vipassana Buddhist meditation. It involves perching on a cushion for 10 hours at a time in utter silence for 10 days. Me, I’d opt for the cooler instead. But several inmates signed up, and the results were so amazing that the jealous prison chaplain had the program shut down. The filmmakers — Andrew Kukura, Jennie Phillips, and Anne Marie Stein — do best when they concentrate on the prisoners’ own testimony and don’t go off on loopy re-creations. And though the anecdotal evidence compels, more-scientific back-up is called for. Nonetheless, when a convicted killer forgives the person who murdered his own daughter, even the most skeptical might be swayed. 76 minutes | Coolidge Corner