According to police, an undercover detective saw a pair of customers ask one of the two vendors for a magazine compatible with a .223 caliber AR-15 rifle.
Police said the customers were sold what appeared to be a 30-round magazine and after interviewing the detectives, police confirmed the magazine was illegal and then confiscated it.
According to Maryland law, magazines that hold over 20 rounds cannot be sold or purchased, county police said.
Later that day, the detectives approached the vendor and asked to purchase a 30-round magazine. Police said the vendor told he could not say "30-round magazine" in Maryland, but that the magazine could be purchased.