Deliberately kill people?
I don’t recall. Did the TV Simon Templar ever deliberately kill anyone? Wiki does not say.
I don’t recall the series well enough to be sure, but I think he kills several side-kicks, at least. And there’s at least one episode where the villain dies fighting The Saint, although he could have been saved.
An Italian crime lord re-living the glory of Rome at his mansion (orgies, gladiators, etc.) ends up in a sword fight with Templar but finishes up in his lionpit and dies.
The Saint despised blackmailers and thought they all deserved the death penalty. This was one of the main differences between the book and the TV series. He hardly equated getting rid of such vermin as murder.