Lieutenant William Derr Promoted to Captain

The Hawaiʻi Police Department is pleased to announce the promotion of William Derr to the rank of captain, effective Jan. 1, 2026. Derr, a 23-year veteran of the department, has been assigned to the North Kohala District.

Derr began his law enforcement career with Ka‘ū Patrol and later served in Puna Patrol. While assigned to patrol, he also worked as a field training officer and, in 2007, was promoted to police officer III and assigned to the Hilo Community Policing Section. He was promoted to sergeant in 2013 and returned to Puna Patrol, where he served until being promoted to lieutenant in 2017 and assigned to Hilo Patrol.

In 2020, Derr became the lieutenant of the Hilo Community Policing Section. Since that time, he has established an extensive network of partnerships and collaborations with county agencies and community groups to expand outreach efforts benefiting keiki and kupuna alike.

“Captain Derr has extensive experience in community policing and has always prioritized community engagement,” said Interim Police Chief Reed Mahuna. “I am excited to see what he can do in his new role and look forward to him taking that experience and commitment with him to benefit the Kohala community.”

The Hawaiʻi Police Department congratulates Captain Derr on his promotion and looks forward to his continued leadership and service to the North Kohala District.