An Arlington man has been indicted in connection with a series of armed robberies in and around the area of Porter Square and Harvard Square, Middlesex District Attorney Gerry Leone said today.

Jonas Moses-Gilson, 19, of Arlington, was indicted by a Middlesex grand jury on charges of masked armed robbery (three counts), kidnapping, assault and battery (3 counts), armed assault with intent to rob and resisting arrest.

An arraignment date has not yet been scheduled.

"I want to commend the excellent, cooperative police work conducted by the Cambridge, Somerville, MBTA and Harvard Police Departments in this case," Leone said.

As a result of several recent armed robberies in the Porter Square and Harvard Square areas by a suspect matching the same description in each, Cambridge, Somerville, MBTA and Harvard Police Departments set up and conducted surveillance in Cambridge and Somerville.

At approximately 11:30 p.m. on Friday, May 22, Cambridge and Somerville Detectives were working together in the Elm Street area in Somerville when they observed the defendant, matching the description of their suspect, approach a male subject who was walking on Elm Street. The suspect displayed a knife and held it near the victim’s throat.

Fearing for the safety of the victim, the detectives immediately moved in and identified themselves as officers, causing the suspect to flee. A brief foot chase by Somerville and Cambridge Police ended inside the Porter Square MBTA station, where the defendant was apprehended.

He was arraigned on May 26 in Somerville District Court on charges of armed assault with attempt to rob and assault with a dangerous weapon. Somerville District Court Judge Maurice Flynn ordered Moses-Gilson held pending a dangerousness hearing.

These indictments against the defendant now include additional charges in connection with three armed robberies that occurred in the Porter Square and Harvard Square areas in May.

These charges are allegations, and the defendant is presumed innocent until proven guilty. The investigation is ongoing.

The prosecutor assigned to this case is Nicole Allain.