Four men wearing black clothing and ski masks entered Ben Bridge Jeweler just after 8 p.m. One man armed with a gun corralled workers and customers to a side of the store, while three other men used a hammer to smash a jewelry case.
The gunman fired his weapon several times in the air, but no one was hurt. Police later learned the weapon was a nonlethal airsoft gun.
The men took off with 25 to 30 Rolex watches, according to police.
The mall was locked down for about 4.5 hours because of reports that the suspects went back inside after being spotted by security. Officers screened shoppers to ensure the suspects didn't blend in with the crowd.
No suspects were found after an extensive search of the area.
Police said this was a carefully planned out robbery, and that the thieves knew exactly which case to break.
"They've obviously done their homework on this," said Sgt. Ken Pollich of the Montclair Police Department. "To go into an open mall setting like that and do a window smash with the amount of people present is very brazen."
Investigators released surveillance video of the crime, hoping it will help them catch the suspects. Anyone with information was asked to call Montclair police at (909) 621-4771