Terminology of the killer to surviving victim.... I could be wrong
Supposedly, according to crime library's account, the killer instructed one young victim to hand over his "britches" ..... meaning pants or trousers.
It seems to me that the term "britches" was a term used perhaps in various geographical areas but not all. I doubt it was a term used in the big cities like Los Angeles, New York, or Boston. So, the killer probably was from a rural area and definitely of a certain age bracket because its an old term that I heard uttered by my grandmother who was raised in farming community in Canada.
As to the killers ultimate end, I'd bet he was locked up in prison for some other crime and maybe even died in prison. I know thats what happened to the prime suspect... but he got out. As for the manner in which the murders took place, I'd say it wasn't the prime suspect because serial killers don't revert to normal and it sounded like the car thief guy who was the prime suspect did get out of prison and there were no reports of gunshot murders around his location post prison.