Suffolk County District Attorney Daniel F. Conley today announced new charges against a man accused of gunning down a Jamaica Plain store clerk during an armed robbery late last year.

The Suffolk County Grand Jury today returned indictments charging EDWARD CORLISS (D.O.B. 2/7/46) of Roslindale with four counts of witness intimidation for allegedly seeking the murders of three witnesses in the case already pending against him.

Corliss was indicted in February on charges of first-degree murder for the shooting death of 39-year-old Surendra Dangol, armed robbery while masked for allegedly robbing the Jamaica Plain convenience store in which the Somerville resident worked and died, and unlawful possession of the .380 caliber semiautomatic handgun he allegedly used in the Dec. 26, 2009, incident.

The latest indictments come after a four-month investigation by Boston Police and Suffolk prosecutors assigned to Corliss’ case. That investigation developed evidence that Corliss, while held at the Massachusetts Correctional Institution at Cedar Junction awaiting trial, sought to have a soon-to-be-released inmate murder three individuals he believed had provided authorities with evidence against him. Those attempts account for three of the latest indictments; the fourth stems from his alleged offer to pay the inmate for the murders and his silence with proceeds from an armored car heist he claimed to have planned.

In 2006, Massachusetts lawmakers expanded the state’s existing witness intimidation laws after extensive input from Conley and other public safety officials. Corliss was charged under language that provides for up to 10 years in prison for attempting to cause physical injury to a witness or potential witness, or for promising any thing of value to a person with knowledge of a crime.

Additional details are expected to be revealed at Corliss’ arraignment at 2:00 tomorrow afternoon in courtroom 906 of Suffolk Superior Court. Assistant District Attorney Patrick Haggan, Conley’s chief trial counsel, is prosecuting the case. Catherine Yuan is the DA’s assigned victim-witness advocate. John Hayes represents Corliss.