Lt. Richard Bolduc's gun has also been confiscated, the Boston Globe reported.
Police in Sandwich, Mass., say that Bolduc's son brought the unloaded gun to a neighbor's house, pointed it at a 5-year-old girl and pulled the trigger. He faces charges that include assault with a dangerous weapon.
The son showed police an unlocked dresser drawer where he said he had found the weapon.
Michael Miller, the police chief in Sandwich, said he was concerned because the gun is a semi-automatic which might have had a bullet in the chamber even though the magazine had been removed.