Harrison Thorp 7:04 a.m.
Tuesday, December 22, 2020 7:05 am

The emergency parking lot at Frisbie Memorial Hospital (Rochester Voice file photo); inset Tyler Thurston (Rochester Police photo)

ROCHESTER - The New Durham man arrested in a deadly assault on a hospital security guard now faces up to 30 years in state prison after the Strafford County Attorney's Office announced on Monday it would add a manslaughter charge following the victim's death on Friday.

Tyler Thurston, 29, is accused of punching Frisbie Memorial Hospital security guard Richard Semo, 64, in the face around 3:20 a.m. on Dec. 13.

Rochester Police say Semo. of Farmington, then fell hitting his head on the pavement in the hospital's emergency parking lot. He was unresponsive when police found him.

According to an affidavit obtained by The Rochester Voice, as four Rochester officers responded to the scene one noticed Thurston, whom they knew "from a prior law enforcement contact," sitting on a wooden fence." The officer noticed blood on Thurston's right hand.

Soon after the attack hospital staff performed a CT scan, which showed Semo had a brain bleed, the affidavit states.

Semo died on Friday at Portsmouth Regional Hospital where he was taken following the attack.

The results of an autopsy performed Sunday have still not been released.

Thurston remains at Strafford County Jail. He is being held without bail.