UO Second Age

I used Forensic Evaluation on a player in town and discovered that they were a Thief (a message popped up saying so & so is a Thief!). But their name remained blue to me, should it not turn grey once I've successfully exposed them as a Thief? How do I attack Thieves in town if their name remains blue?

If im correct, that just means he's in the thiefs guild, not that he has stolen and gone grey