Detectives Rene Alicea and Joseph Aboyoun of the Street Crime Unit were in the 200 block of 12th Avenue around 1 a.m. Saturday when they saw the victims with their hands in the air, Police Director Jerry Speziale said.
The robber -- identified as city resident Nicholas Williams, 25 -- started to walk away when he saw the detectives emerge from their unmarked vehicle, Speziale said.
Williams tossed the gun and tried hiding behind a car, where the detectives grabbed him , the director said.
The victims were gone when they looked back, he said.
The detectives collected the .45-caliber semi-automatic handgun and brought Williams in.
He was charged with aggravated assault and weapons offenses and sent to the Passaic County Jail.
The gun was sent to New Jersey State Police Ballistics Laboratory to determine whether it had been used in previous crimes, Speziale said.
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