A single bullet that may have been fired in celebration of the New Year ripped through the wall of a house shortly after midnight Tuesday, killing an 11-year-old girl and a woman attending a party inside, investigators said.

A 25-year-old man was later arrested at his home on investigation of two counts of first-degree murder, police spokesman Sonny Jackson said.

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"It might have been an accident, which still would be illegal if someone was firing a weapon recklessly in the city," Police Chief Gerry Whitman said.

Investigators believe the weapon was a high-powered rifle, Whitman said. The shot was fired at about 12:20 a.m., and the shooter may have been a New Year's reveler celebrating the New Year, Jackson said.

Witnesses reported hearing several shots, and a second bullet was found in a snowbank in front of the home.

The victims were at a party with about 10 other people when the bullet pierced the front wall of the house, passed through the head of the woman, who was seated, and struck the girl in the side, Jackson said.

The woman died at the scene, and the girl was pronounced dead at a hospital.

Investigators believe the shot was fired from as far as 300 yards away, possibly from across a greenway flanking a path near the house, investigators said.

Police said they used lasers to trace the trajectory of the shot and to determine that one bullet killed both victims.

The house is in a neighborhood of modest single-family homes, duplexes and apartment buildings.