Hmmm interesting, perhaps the reason he was out and about at 3:30 am is that he was up to something he'd rather not admit, given his rather dubious past. He happens on the fire and does the right thing only to be arrested on the suspicion he started it. An 'alibi' along the lines of 'I was there looking to steal a car or break into a house' wouldn't help him much. LOL.
On the other hand, given that he is effectively a loser except for the time he rescued those people in the previous fire. He must have been feted and applauded at the time. Liking the attention he wants to relive it. So he sets a fire and rescues the occupants expecting the same praise and relief from his troubles. Only for the cops to finger him straightaway because being a loser, he leaves too much evidence.
No doubt the courts will decide.
