EDISON — Police are looking for the gunman who robbed a gas station and then killed the clerk with a single gunshot on Thursday morning.

The clerk, identified as John Bertram, 38, of the Fords section of Woodbridge, handed over a cash register drawer to an armed robber inside the Speedway gas station on Amboy Avenue in Edison around 4 a.m., according to Middlesex County Prosecutor Andrew Carey. As the suspect left the store he fired a single fatal shot at Bertram.

Police respond to a shooting at a Speedway on Amboy Ave in Edison (RLS Metro Breaking News)

At a news conference at the Speedway, Carey said a second employee was not injured.

Carey described the masked suspect as a "male of slight build" wearing light-colored pants, possibly jeans, a maroon hooded sweatshirt, and gloves. Authorities did not provide any description of any possible getaway vehicle.

The Edison school district warned parents and students about the incident in the Clara Barton section but said schools were open.

Edison Mayor Thomas Lankey expressed confidence that law enforcement would find the suspect.

"I have confidence in our police department's investigative capabilities, working alongside county prosecutor's detectives, to find and bring the perpetrator of the heinous crime to justice."

Carey asked anyone with information about the shooting to call Edison police at 732-248-7531 or the Prosecutor’s Office at 732-745-4436.