One of three men wanted in connection with last month's brazen $4 million armed robbery in the Diamond District has been arrested, federal prosecutors said Tuesday, but the alleged ringleader remains at large -- and he's thought to be armed and "extremely dangerous." 

Pedro Davila was taken into custody Sunday night in Florida and is expected to appear in federal court there later Tuesday. Prosecutors say Davila, the alleged ringleader Jaysean Sutton, and a third man all walked into Avianne & Co. Jewelers on 47th Street between Fifth and Sixth Avenues Aug. 25, pretending to be customers, then flashed guns and tied up employees in a back room before fleeing with jewelry. Facial recognition technology identified Davila and Sutton. 

Both men face charges including robbery, robbery conspiracy and brandishing a firearm; the federal weapons charge includes a maximum sentence of life in prison. Information on a possible attorney for Davila, a 27-year-old from the Bronx, wasn't immediately clear. 

Authorities are still looking for Sutton, a bald 39-year-old man about 6 feet tall with brown eyes who is believed to have been in the Stamford, Connecticut, area, law enforcement sources have told News 4. He was also known to hide out in New Jersey, though it wasn't clear where, the sources said. 

Sutton is the man seen in widely watched surveillance video wearing a suit; he has long hair and sits at the table before pulling out a gun. Sutton has been arrested before, most recently in February on weapons and drug charges. He is believed to be armed and extremely dangerous, the sources tell News 4.

Davila has been arrested before but not for violent crimes; he has a large mole by his left ear. The third suspect remains unidentified. 

"In the day and age of technology and cameras, you would think robbers trying to pull off a cinematic heist would think twice. But these men allegedly took over a jewelry store in Midtown, tied up the employees and robbed it without believing they would get caught," FBI Assistant Director-in-Charge William Sweeney Jr., said in a statement. "Their mistakes should be a warning to everyone wanting to be a copycat, you will get caught and pay the price for breaking the law."

Officers for the NYPD's Major Case Squad have been investigating the brazen daytime heist for weeks. Surveillance footage released by NYPD shows the robbery suspects holding handguns as workers lay face down on the floor. They then grab jewelry and threw it into a duffle bag before running off on foot.

Eli Ariah, who spoke to one of the victims moments after the robbery, said he was told about $4 million worth of jewelry was taken. 

"We came in to open up the store these guys came in pretending like their customers and they pulled out guns and robbed us. They told the boss to open the safe," Ariah told News 4.

None of the victims was physically hurt, police said. No arrests have been made. Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS.