Captain Murderer
Captain Murderer was the captain of the Queen of Quirm, and a member of a highly-respected Quirm family. It is believed that they are rather keen on the name.
After he was caught by the Quirm City Watch and Samuel Vimes with a hold full of goblins and a kidnapped Jethro Jefferson, he was in deep trouble. Captain Murderer chose of "his own free will" to name names and point fingers at those who had greater complicity in the crimes. Alternatively he could have chosen of his own free will to watch Vimes burn his ship to the water. As it was Vimes spared the ship, content to bring it back to Quirm Docks until further notice.