JERUSALEM — Security camera footage of a deadly Israeli arrest raid in a West Bank hospital on Thursday gave a rare glimpse into the murky undercover units that Israel contends are a key tool in preventing violence and Palestinians revile as a ruthless symbol of Israeli occupation. In the footage, Israeli officers disguised as Palestinian civilians in Arab garb, including some wearing fake moustaches and beards or dressed as women, burst into the hospital and dragged away a wanted Palestinian in a wheelchair. The pre-dawn raid in the volatile West Bank city of Hebron, outraged Palestinians and drew accusations that Israel had improperly used force in a building that should be immune, or at least insulated, from military operations. The hospital released security camera footage showing about a dozen men entering a hospital ward shortly before 4 a.m.