Kevin Tighe .... Paramedic Roy DeSoto
I knew it was Kevin Tighe, as I've seen him in loads since "Emergency" - so as said, I just got me 70's shows mixed up.
Yes, what you explained makes sense... BUT... are you saying he is NOT really Locke's father? Then I will buy that he's just evil. But if he IS Locke's father, and he just bailed after his own son gave him a frickin' kidney... I need more than just 'he's evil'. Ya know?
(Martin Milner was the blonde from Adam 12... both shows had a dark/light duo... ala Starsky & Hutch, Dukes, etc.)