At the press screening of Praying With Lior, many of the critics around me openly sobbed. This doc is a hardcore tearjerker. Its subject is a Jewish boy with Down syndrome preparing for his Bar Mitzvah; Lior Liebling enjoys leading others in prayer so much that he is known as “the Little Rebbe.” His mother died of breast cancer when he was six, and director Ilana Trachtman milks the boy’s honest, simple sorrow for all it’s worth. We get ample footage of “Mommy Devora” singing with Lior, playing with Lior, and, yes, praying with Lior. Trachtman’s movie is not technically accomplished—the camerawork is run-of-the-mill, the structure is rambling—but it’s redeemed by the deliciously complex, practically Balzac-ian family at its center. Lior’s father, Mordechai, is a prominent rabbi who demands a great deal from his son even as he adores him. Stepmother Lynne is devoted to Lior, but her place among the Lieblings seems precarious and hard-won. Lior’s siblings are thoughtful and frank about the challenges of living with their brother and longing for their mother. Everyone still reels from the loss of Devora, whose fierce love for both her children and her religion dominates the film, almost against the family’s will. I would have liked to see Trachtman focus more on these dynamics and less on Lior’s sunny, prayerful disposition. He is undoubtedly a charmer, but this is a kid with limited verbal abilities—he’s retarded, as his father bluntly puts it—and Trachtman’s prodding, leading questions make the endeavor distinctly uncomfortable. At times, the film dances perilously close to painting him as a holy fool, rather than a boy who loves to pray and lives to please.