NORTHPORT - ? Cops are searching for a dangerous serial bank robber that is on the loose on Long Island.

Cops have released surveillance pictures and say the man has walked into six banks in the last three months armed with a gun and his finger on the trigger. Investigators say the man made off with cash at five of the banks, including one last night at Chase in Northport on Fort Solanga Road.

The other banks the man hit were in East Northport and Manhasset last month, then again in Manhasset in May and last Friday in East Hills.

Police say the man has the same motive every time, wearing a loose button down shirt over a T-shirt, hat and sunglasses, and always carries a specific blue and black bag.

Detectives are asking anyone with information on this incident to contact Crime Stoppers at 1-800-220-TIPS.