Fun! I think Peter played that role several times in "The Untouchables" -- mad-dog killers were a specialty of his, in those days. I imagine Val Avery wasn't the only player that Peter knew before "Columbo" -- he seemed to enjoy working with friends and with pros he already knew would come through.
I often watch the 70's shows on METV and i always see characters that i know from Columbo; since a lot of the shows are from 'Universal Studios'. A couple examples are Mission Impossible and The Twilight Zone.
I drive my wife crazy when i see a familiar actor and i'll say his character name from Columbo, like "Hey , there's Mr.Pauly"
It works even for the newer episodes. I can never watch Death Hits the Jackpot without looking at the son of the Penny Santon character and shouting out "That-a Johnny Depp, he make-a me cry!"
I know that Peter was in a very strange early ' 60's movie with Lee Grant, but I can't think of the title. (I found it on one of those lists of "borderline" weird movies on a horror and SF site.)
And of course Peter was in the Twilight Zone episode "The Mirror," and that had Arthur Batanides of "Mind Over Mayhem."