There is one basic physical crime against another's person: Assault.
This can be further subdivided into two specific charges: Physical assault that causes the other person's death, which we give the high-falutin' Latin name "homicide", and physical assault that doesn't do so.
A subcategory of the second kind is assault of the type, involving the sexual organs, which we call "rape".
Now, generally speaking, we recognize some possible rationales for these kinds of physical assault. For instance, there is the "self-defense" claim, in which it is claimed that the final victim was trying to do That Thing to the perpetrator first. To wit: "He tried to kill me, so I killed him before he could do so," or "She punched me in the nose, so I punched her back."
Then there is the defense of "It was an accident." For instance, "I was driving along in my car when she ran out in front of me," and "I was going for the slam-dunk and I didn't mean to hit him in the throat with my elbow there under the net."
Lastly, there is the claim of "I was just frickin' crazy and didn't know Right from Wrong," where the perp's excuse is "I was just frickin' crazy and didn't know Right from Wrong."
In the first and second incidences, we realize that there were mitigating circumstances. In the third, we realize (or used to) that the perpetrator is as crazy as a rabid dog and warehouse them away from normal people or dispose of them dispassionately.
Rape is an unusual type of physical assault in that it is hard to claim either of the first two mitigating circumstances: Both self-defense ("The altar boy was coming right for me!") and accident ("I tripped and fell on top of her and my you-know-what accidentally landed you-know-where") ring pretty hollow as defenses, and that leaves only the third excuse, the one where we realize that the perpetrator is as crazy as a rabid dog and warehouse them away from normal people or dispose of them dispassionately.
Watching people who should damned well know better reach for one of these excuses to cover one of their own is positively sick-making.