COMMACK - Police are trying to determine if a knifepoint robbery at a Carvel in Commack Tuesday night is connected to nearly a dozen other knifepoint robberies of Nassau businesses.

Police say a man in a black hooded sweatshirt held up the ice cream shop on Commack Road around 9 p.m. Tuesday. No one was hurt.

Suffolk County Police Department Chief Stuart Cameron says the suspect in this case fits the description of the same man who has robbed 11 stores in Nassau county since early March.  

Cameron says in each case, including Tuesday night's robbery, the suspect waits until an employee is isolated, walks in and threatens that person with a knife.

"It appears that this suspect stakes out the stores, to wait for an opportune moment when there are no customers in the store," he says.

Nassau's knifepoint robber has hit two Carvels, six Dunkin' Donuts, two Subways and a 7-Eleven.

Anyone with information is asked to call Suffolk detectives at 1-800-220 TIPS.