Does anybody know if the Internal Affairs generally hired any hitman because.....?

I'm an ACCA and I write in my free time or go out with the family. I'm writing a novel and i have completed my 1st novel. Though not thinking about publishing it. So now I'm working on my second novel and its plot is an Interna Affairs hired hitman falls in love with a walmart female supervisor. The woman finds out that he's a hitman and he tell her finally that it was him who gunned down the governor of new mexico and mayor of LA. I wouldn't leak out the whole story. I just want to know that did or does the internal affair ever hire a hitman? I know they send undercover agents but i haven't heard about a hitman. If they don't/didn't, then what do you think i should write instead of IA?