I read this at least fifty years ago so very faint memories - an anthology in the UK - no thoughts on the cover or any other stories.
This guy is carrying on his humdrum life, one evening he's in some club or restaurant and an uncontrollable urge takes him over.
He hurries across town (I think it was in the United States) and enters an office block, he charges through into an office where an executive or politician is behind a desk. The protagonist feels his mouth open wide and a laser beam fires out and kills the target.
He then returns to the club and he's released from the compulsion. I think he's then trying to deal with learning he's a robot for a few pages but the kill control takes over again and again ... Until he tries to seek out the controllers.
That's really all I remember