Evanston police say a citizen caller reported a man waiving a gun out of a dark work van in the area of Emerson Street and Dodge Avenue about 10:42 p.m. Thursday.
Police Cmdr. Joseph Dugan says responding officers spotted a vehicle matching the description nearby in the 1800 block of Darrow Avenue.
The officers conducted a felony stop on the vehicle, which had three adults inside.
The officers didn't find any weapons, but one of the men, Christopher D. Boyd, 24, of 1802 Lemar Ave., was arrested and charged with felony possession of 4.6 grams of crack cocaine and misdemeanor possession of 3.8 grams of cannabis.