The beautiful, terrifying domestic drama “We Need to Talk About Kevin” won the London Film Festival's best-picture prize Wednesday. Lynne Ramsay's film stars Tilda Swinton as a mother grappling with grief and guilt after her teenage son carries out a high-school massacre. “Shakespeare in Love” director John Madden, who chaired the judging panel, called it “a sublime, uncompromising tale of the torment that can stand in the place of love.” The 55-year-old London festival introduced a best-film prize two years ago as part of a bid to boost its profile and compete with better-known events in Berlin, Venice and Toronto. “Kevin” beat eight other finalists, including French silent movie “The Artist,” Aleksandr Sokurov's Venice Film festival winner “Faust” and British director Steve McQueen's body- and soul-baring “Shame.” Nineteen-year-old actress Candese Reid was named best British newcomer for her role in gritty drama “Junkhearts,” her first professional acting role. Argentinean director Pablo Giorgelli won the festival's best first feature prize for his Latin American road movie “Las Acacias,” which picked up the same award at this year's Cannes Film Festival. The best documentary trophy went to German auteur Werner Herzog for his death row portrait “Into the Abyss.”