I am somewhat shocked at this question as I feel like you didn't even try to make a good showing with it (such as by trying to at least argue that the prisoner wanted the interaction for something other than a tit-for-tat way to alleviate their court mandated suffering)... yes, 100% absolutely: someone who is in a shitty situation (being in jail) that someone who has some power over them (a guard) is parlaying into "have sex with me and maybe you will get a favor" is a victim.