Police say a 21-year-old man from Calverton has been arrested after pointing a gun at a driver on the East End.

Riverhead police tell News 12 they received a call Tuesday morning from a driver saying he was going through the Peconic River parking lot when another man became agitated and pointed a gun at him in a threatening manner.

When officers arrived, they arrested Matthew Pittman. Police say Pittman had two guns in his car.

During the investigation, police say they linked Pittman to two previous robberies that happened on Sunday - one on Third Street in Riverhead.

In that robbery, police say Pittman pulled a gun on a man on Third Street and demanded his cash.

Then about an hour and a half later, police say Pittman went to the Mobile Gas Station on Old Country Road in Riverhead, pulled out a gun and demanded cash from the clerk. The clerk complied, but police say Pittman shot at him at least 11 times as the clerk tried to run away.

Detectives say one of the guns Pittman used was a 9-millimeter ghost gun.

Pittman is facing more than a dozen charges. 

In addition, police say two 17-year-old boys have also been arrested and are accused of helping Pittman in two of the robberies.