NEWARK, Del. (CBS) — A Newark police officer suffered a serious head injury after being tripped by a suspect who was being arrested, authorities say. Newark police say the incident happened on March 23 at police headquarters.

According to police, 19-year-old Alexander Mastronardi, was initially taken into custody for allegedly refusing to let go of the door handle of a woman’s car on North College Avenue in Newark. Police say Mastronardi initially tried to punch the officer before he was taken to the station.

While at Newark Police headquarters, Mastronardi, who was intoxicated, resisted and struggled with the officers, police say. Mastronardi then threatened the officers and tripped one of them with his legs. The officer struck his head on a metal counter and fell to the concrete floor.

The officer was admitted to the critical care unit at an area hospital in serious condition, where he remained for over a week. He has since been transferred to a rehabilitation center for further treatment.

Mastronardi was charged that evening with misdemeanor offenses related to the incident and was released, however, on Monday, he was taken into custody to face more serious charges.

Mastronardi has been charged with assault on a law enforcement officer, resisting arrest with force or violence and other related charges.

He was ordered held on $32,400 secured bail and is being held at the Howard R. Young Correctional Facility in Wilmington.