From Grimm wiki
Sgt. Wu
Sergeant Drew Wu is a dedicated officer with the Portland Police Bureau who serves as a loyal colleague and friend to Nick Burkhardt and Hank Griffin.
Role in the Portland Police Bureau
Sergeant Wu is a long-standing member of the Portland Police Bureau, frequently providing essential support for the investigations led by Nick Burkhardt and Hank Griffin. Initially unaware of the supernatural world surrounding his colleagues, Wu often handled the technical and logistical aspects of police work, including crime scene processing and evidence management.
Discovery of the Wesen World
Wu's perspective shifted dramatically after he suffered a traumatic encounter with an Aswang, which forced him to confront the existence of Wesen. Following this event, he was gradually brought into the inner circle, eventually learning the truth about Nick's identity as a Grimm. His transition from a skeptical investigator to a trusted ally allowed him to assist in high-stakes cases involving figures like Captain Sean Renard and Adalind Schade.
Personal Development
Throughout the series, Wu proves his value by applying his police expertise to the complex threats faced by the group. He develops a close bond with other allies, including Monroe and Rosalee Calvert, and remains a steadfast protector of his friends despite the dangers posed by the hidden supernatural community.