... It appears that Holmes intended to blow up the apartment after he left for the movie theater by planning to ways to start the fire remotely.
The first was a trip cord connected to the door. After he left the apartment, Holmes started a recording in his apartment that was 40 minutes of silence followed by blaring music.
He thought the noise would prompt one of his neighbors to call police and that responding officers would break into the home through the front door, starting off a series of explosions.
The other plan was a remote control that he left outside his apartment, next to a remote-controlled toy car. If police didn't respond to the noise complaint. He thought someone would see the car and try to play with it using the remote, which was in fact a trigger. ...
Extra credit for imagination, I suppose.
