Lavallette Chief Colin Grant was arrested late Friday night at his home in nearby Toms River.
Officers had gone there for a reported domestic dispute, and the 40-year-old woman told police that Grant had physically assaulted her during an argument.
The 48-year-old Grant was then arrested after officers saw "obvious signs of injury," including redness and a small abrasion about the woman's neck.
Ocean County authorities say Grant voluntarily surrendered his weapon after the incident. He has taken a personal leave and could not be reached for comment Monday
The Ocean County Prosecutor's Office will conduct an administrative internal investigation independent of the simple assault charge.
