How is he going to get a hold of the dude when the killer was about to get life in jail or death penalty?
maybe he really did know what he was doing...trying to kill 2 birds with one stone.
on one hand he got to attack the guy face to face in the courtroom. if he was acquitted then at least he did that and would have the chance to track him down later.
if the killer did in fact get jailtime, his actions (the son) in the court could also land him in jail- where he can get acquainted with contacts to start phase 2 of his plan- to get the convict from the inside.
the best of all worlds. hey, he might even get put in the same facility!..
thats called maximising the odds in my book.