Police in an Atlanta suburb have enlisted the help of federal agents to examine a rifle dropped by a man who was seen aiming at a school bus and left behind a notebook with bus numbers.

Clayton County police Officer Phong Nguyen says the Bureau of Alcohol, Tobacco, Firearms and Explosives will try to obtain leads from the weapon, a Marlin .22-caliber rifle.

The Atlanta Journal-Constitution reports that more than 50 officers spent Wednesday afternoon going door-to-door in the neighborhood where witnesses saw the man aiming at the bus Monday morning.

The man fled when witnesses confronted him. Authorities say a neighbor chased him, but stopped when the man used a second gun and shot at him.

Police recovered the rifle and a notebook filled with bus numbers.