"As you know, I am a candidate for sheriff of Orange County," Chief Birkhead stated in his resignation letter. "I feel that I should devote all of my energies to my campaign. Under the circumstances, I feel it is best for the Town of Hillsborough and my campaign to step down."
Birkhead, 49, has served as Hillsborough's police chief for almost five years.
Town Manager Eric Peterson hopes to name an interim chief by early next week.
"We are all thankful for the many improvements Chief Birkhead has made over the past five years to improve the quality of policing that's been provided to Hillsborough's citizens," Peterson said.
The search for a new chief is expected to take about six months.