Monroe is a Wieder Blutbad who used to live a fairly solitary, reformed life among humans, until he met Detective Nick Burkhardt during a case.

Because Nick often calls Monroe for help on his new Wesen cases, they form an unlikely friendship as a result of it. Most times Monroe is consulted for his knowledge about the creatures of the Wesen world, when Nick can't find the answer. He helped him in many ways: from tracking suspects to protection and investigative methods. He met his wife Rosalee while he was helping Nick on a case.