who kills the narrator's boss?

Tyler killed his boss. The narrator realizes that the police will be looking for him. He was the last one in the building before the mechanic picked him up from work. He had smelled gasoline on his hands. He knows that his boss’s computer monitor was drilled into with a jeweler’s drill and the cathode ray tube inside it was filled with gasoline. When his boss sat down to turn on his monitor, it had exploded right in front of him.