Nightwatch (1997) ending / spoiler
Inspector Thomas Cray is behind the murders, he used to be the previous nightwatchman with the necrophillac tendencies. Katherine twigs it's him when he whistle's 'THIS OLD MAN' which she heard after she stumbled across the murder scene of Joyce.Deputy Inspector Bill Davis is beaten to death with a baseball bat by Cray who leaves James Gallman handcuffed to an overhead pipe. In order to free himself, James ends up cutting his own thumb off. Just before Cray can perform DIY labotomy on Martin and Katherine, he gets two bullets in the back followed by one in the throat from James.