Does this apply when an 18 year old girl screws her 17 year old boyfriend on prom night? What about a 19 year old young man marrying a 15 year old girl, as occurs in my own family tree not too many generations back? Or a naive and immature and foolish 21 year old babysitter who “makes a man” out of a horny 13 year old boy in her care? And that’s apart from witch hunts with zero physical evidence like the McMartin Preschool case. There are shades of grey here, unfortunately.
I’d say to make death an option in cases where an adult rapes a pre-pubescent child, to be applied in cases aggravated by torture, physical injury, transmission of a deadly disease such as HIV or hepatitis, a very young victim (under age 7 perhaps), repeat offenses, etc. If you make it mandatory, a lot of victims would be killed to eliminate the witness.