I'm trying to track down a sci-fi short story my mom read ages ago. It must have been the late 70's or early 80's. I think it was in an anthology, but I could be mistaken.
A slug-like alien is arrested for murder, because the police (or whoever arrested it, I'm not sure), think it ate another alien. However, it turns out that the other alien is a doctor, and treats his/her/etc patients from the inside.