A Boston hospital worker accused of sexually assaulting two patients is now facing charges involving additional victims, according to the Suffolk County District Attorney’s Office.

Damian Knighton, a 39-year-old medical assistant of East Boston was arrested in January and charged with the rape and indecent assault of a patient at the Massachusetts General Hospital Back Bay Health Center on Commonwealth Avenue. Days later, he was charged with indecent assault and battery against a second patient at the same hospital.

The Suffolk County District Attorney’s Office said Monday that Knighton had been indicted on seven new counts of indecent assault and battery, with four victims involved. It was not immediately clear whether the previously known victims were included in that total.

Knighton will be arraigned on the new charges on June 29 at Suffolk Superior Court.

In the first case, the victim told police he was going to the hospital for a follow-up appointment regarding an injury to his shoulder and right leg. That was when Knighton approached him, allegedly telling the victim that the doctor had requested another test, and had the victim remove his clothing.

The victim said Knighton brought him into an examination room where he asked him to kneel on the examination table, and inserted a finger into his rectum, before being asked to turn around and sit on the examination table, where he inserted a finger into the victim’s rectum for a second time.

After the victim got dressed he went to the front desk and told staff that he felt that he had been sexually assaulted and wanted to report it.

Police were called to the hospital and Knighton was arrested and charged with two counts of rape and indecent assault and battery.

In the second case, the victim reported their experience, which happened on Jan. 12., after learning about Knighton’s arrest. He reported that Knighton led him to an exam room and sexually assaulted him after asking the victim to take more medical tests, according to officials.

The hospital said at the time of his arrest that Knighton had been placed on administrative leave.

Any patient of Knighton’s who believes they were assaulted under similar circumstances to contact the Boston Police Department Sexual Assault Unit at 617-343-4400.

This is a developing story. Check back for updates as more information becomes available.

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