Police say they have uncovered a possible murder weapon as they question a person of interest in connection with the fatal shootings of three Brooklyn shopkeepers.

According to investigators, a Staten Island man, identified only as "John Doe Duffel Bag," is in police custody at the 67th Precinct. He was seen on surveillance video near the scene of the latest killing in Flatbush last Friday.

Authorities say they recovered a duffel bag and found a sawed off .22-caliber rifle, which is the same type used in each murder. The bag also contained knives, ammunition, black gloves and women's stockings.

In all three cases, police say the killer targeted shops near closing time that did not have surveillance cameras and were run by older Middle Eastern men. All three victims were shot using the same gun and dragged to the back of their stores.

Anyone with information on the slayings is urged to call Crime Stoppers at 1-800-577-TIPS.