Well, interesting point brought up here. I seldom think of trophies, but since my stories usually involve several different rapists, it stands to reason that at least one of them should have that kink. I've done it in the past, though, but as I said, seldom.
In "Mutiny In Thysville", the Congolese soldiers force the Belgian wives and daughters of their officers to pose for them as they take nude pictures. Since the story is set in 1960, those black-and-white pictures require a lot more effort and logistics than using iPhones and they circulated in copies among the entire Force publique. It is a trophy indeed that I've used to add a sense of irony when I stated that some Belgian generals ended up in possession of some copies.
In "Troops Gang-Rape a French Journalist in Kosovo", the story is illustrated with many pics that are taken by the rapists themselves with some dated device in 1999, so the pics are b & w and grainy. Trophy indeed.
In my current story, General Santa Anna could keep the dress Consuelo wore when she stood on that wall before the final assault, since he found it so cock-teasing. He could have it repaired or replicated and given to his own mistress for his personal enjoyment.