BROOKLYN - Police are trying to track down an armed serial robber who they say is targeting Apple Banks in the borough.

According to investigators, the suspect has struck the Apple Bank on Albany Avenue in Crown Heights three times in the last year and a half. They say on a fourth occasion within that time frame he also held up an Apple Bank on Flushing Avenue.

Authorities say that in each case, the man flashes a gun to tellers and demands cash. It is unknown how much money he has been able to take.

The suspect has been caught on surveillance video and is described as being about 6 feet tall and between 40 and 60 years old, with a salt-and-pepper beard. Anyone with information should call Crime Stoppers at 1-800-577-TIPS.