Imagine Old Joy reconceived as a horror movie and you’ll be at least partially prepared for Trigger Man, the startling sophomore feature by 26-year- old writer-director (and Larry Fessenden protégé) Ti West, whose vampire-bat epic The Roost played briefly back in 2005. Working from the purportedly true story of three buddies on a Delaware hunting trip attacked by an unseen sniper, West fashions an uncommonly naturalistic terror tale in which the emphasis on landscape and the passage of time owes less to cut-and-run splatter-cinema hallmarks like Last House on the Left and I Spit on Your Grave than to the work of experimental filmmakers like Michael Snow and Chantal Akerman. Rife with echoes of 9/11 and the Virginia Tech shootings, Trigger Man denies its audience conventional narrative satisfactions while creating an almost unbearable atmosphere of voyeurism and random violence, right up to a final scene that teases us with resolution, only to devolve into yet another enigma. Who’s gunning whom in Trigger Man? The point is that it scarcely matters in a world where everyday life has become a deadly contact sport.