OLD BRIDGE, N.J. — An ex-Marine who had suffered from depression and once tweeted about killing “everyone I see” opened fire in camouflage gear at a supermarket early Friday, gunning down two co-workers before he killed himself, authorities said.

Terence Tyler, 23, left his night clerk shift at a Pathmark store in Old Bridge Township around 3:30 a.m., drove off and returned 20 minutes later to the closed store with a handgun and an assault rifle similar to an AK-47, Middlesex County prosecutor Bruce Kaplan said.

Tyler fired more than 16 rounds from his rifle, shooting at an employee standing outside and firing as he entered the store, blowing out the front windows, authorities said. He shot at five other workers in an aisle, killing Christina LoBrutto, 18, and Bryan Breen, 24, Kaplan said.