SALEM – A Revere man who authorities say robbed a Market Square convenience store of about $300 last month has been indicted by an Essex County grand jury.Joseph M. Gorman, 30, of 134 Bellingham Ave., stands charged with armed robbery in connection with the Oct. 12 holdup at A&A Market.According to reports, it was around 11:30 p.m., when a man, later identified as Gorman, walked into the convenience store, approached the counter and indicated he had something in his right jacket pocket while demanding money.The frightened store clerk turned over between $250 and $300 in cash.Before fleeing the store, the robber also apparently grabbed three packages of Marlboro cigarettes.Police responding to the scene arrested Gorman nearby on Elm Street. Inside his jacket a can of starter fluid and some cash. He was later identified by the victim as the holdup man.Assistant District Attorney Karen H. Hopwood is assigned to prosecute the case for the commonwealth.An indictment is not an indication of guilt; rather a grand jury found sufficient evidence to warrant a jury trial in Superior Court, allowing for a more severe punishment.A conviction on the armed robbery charge carries a potential life sentence in state prison.