Police on Monday arrested three juveniles in an armed-robbery scheme targeting construction contractors in Lincoln Park. Between 10 and 10:30 a.m. Monday, three men held up contractors at two work sites in the neighborhood, says David Kamperin, a D.C. police department commander. Each time, one of the men pulled a black pistol and robbed the workers of their wallets.

The three juveniles were arrested after a tip led police to a home on 19th Street NE, where a search warrant turned up a handgun.

The men were charged with armed robbery. One was also charged with a weapons violation. Kamperin says police are investigating whether they were involved in a rash of contractor hold-ups this year in the First District. Since January, there have been 34 armed robberies in the First District. Six victims were contractors.