When the motorist declined, Arkadyev, 44, told him to jot down his license plate number and call 9-1-1.
Twenty minutes later, Sullivan said, Arkadyev walked into the 7th District's headquarters, at Bustleton Avenue and Bowler Street, and said "something needed to be done" about a problem he had at the Leo Mall Shopping Center, on Bustleton Avenue.
Officer Matthew Quinn noticed that Arkadyev was wearing a bulletproof vest and an empty holster. Arkadyev led Quinn to his Subaru, where the cop found a rifle and two handguns. Arkadyev, of Barlow Street near Kelvin Avenue, was arrested and charged with weapons violations because his permit to carry had been revoked by the city, Sullivan said.
Cops later found 24 rifles, two shotguns and 16 handguns at Arkadyev's home, as well as thousands of rounds of ammunition, Sullivan said. It was unclear if all the weapons had been legally purchased, Sullivan said.
Investigators found receipts for several guns that Arkadyev ordered at suburban gunshops last week, he said.
Sullivan noted that investigators were still unsure what Arkadyev's intentions were on Monday. The man was "incoherent" when he was arrested, and hasn't made much sense since then, Sullivan said.
Two years ago, Arkadyev was stopped at John F. Kennedy International Airport, in New York City, when he tried to take six pistols and three rifles on a flight to Ukraine, Sullivan said.
His license to carry was suspended after Arkadyev caused a scene at the American Embassy in Kiev, where he claimed to be associated with the Philadelphia Police Department, Sullivan said.
Arkadyev emigrated to America with his parents in 1996, Sullivan said, and has no criminal history.