when loreli read the letter from redjohn there was a part were he wrote till u catch me or i catch u, then said he was going to start killing again and more often starting with a happy memory.i thought why would he say till i catch you, he could kill jane anytime. the happy memory lead jane to his his physciatrist and the clue to the catch u line,might have been the fear of of heights she commented on.then  mcallister saved jane on the roof which could  be looked at as catching him