Close-up of Edison gas station robber. (Edison Police Dept.)

EDISON — The manhunt continues Thursday night for the robber who shot and killed a gas station attendant.

Prosecutors on Thursday night said the suspect was still at large after authorities in Perth Amboy announced that a man had been pulled over from a Lyft and arrested, suggesting that the suspect had been found.

"While someone was being questioned regarding the fatal shooting at the Speedway Gas Station in Edison, he has been released from custody," the Middlesex County Prosecutor's Office said.

"The suspect remains at large and is described as a male of slight build wearing light colored pants, possibly jeans, a maroon colored hooded sweatshirt, mask and gloves."

The robbery that left 38-year-old Fords resident John Bertram dead shocked the region just days before Christmas.

Investigators say the robber went into a Speedway Gas Station and held up the clerk with a handgun. Even after getting a cash drawer, the robber shot the clerk once.

Township police responded to the Speedway Gas Station at 4:02 a.m., where they found Bertram dead.