I'm against any government-institution of the death penalty as a whole.
But at the same time, I'd have no qualms about, in the case of an individual like that piece of shit nonce who essentially branded his child victim as 'dirty', administering mob justice. If they were caught in the act, or it was otherwise certain that they did what they were accused of then I really wouldn't hesitate to take them apart, piece by piece.
Not that I'd make an exception for any other rapist if I caught them at it. Thats the sort of crime of passion that would make a murder following it pretty certain (of the rapist). I'm downright pleased with the way an ex of mine responded, when some piece of shit raped her (or tried, I'm not entirely clear which was which, because sadly, she has suffered that way twice that I know of) She carried a long-bladed, rather odd knife, of a type I haven't seen before or since, other than on her. Similar to a lock knife. Well it was a lock-blade, but of an unusual design where it closed up partially, with the blade shortening, and doing into a sheath, where it could be drawn and used without extending it, but extending it would turn it into a shortsword, and sharp as hell.
She grabbed the guy's dick, stuck that funky ass dagger/sword sheath knife/lock blade hybrid thing of hers into the base of his dick and ripped it out again, right down the middle to bisect his knob. Just what the little fuck deserved for it. Think she might well have stabbed several of his associates there at the time (tried to gangrape her, the fucking arseholes, only to be forced to back down after getting the message that anybody who messed with her in that sense is going to end up with two half-dicks.