Magical criminals mean magical crimes and those mean magical cops. Changer cops.
Changes and Changers is a series about the members of the Changer division of the FBI: human Changers, all imbued with the magic of mythological creatures like dragons or unicorns or succubi, all sworn to serve and protect. They enforce the law in the aftermath of the Change, where there are old crimes with new wrinkles and new crimes with newer faces like illegal magical drugs, monster mob enforcers and Changer slave trafficking. This is an ongoing series, with stories emerging through the exploration of the characters and situations involved.