HARTFORD, Conn. (WTNH) — The 18-year-old high school student charged in the crash that killed Hartford Police Det. Robert “Bobby” Garten and seriously injured Officer Brian Kearney now faces manslaughter and assault charges.

State police served Richard Barrington Jr., who has been in police custody since the crash on Sept. 6, an active arrest warrant Thursday. He was arraigned Thursday in Hartford Superior Court on charges of first-degree manslaughter, first-degree assault, first-degree reckless endangerment, disobeying the direction of an officer, DUI, reckless driving and failure to yield to an emergency vehicle.

Barrington was initially charged with failure to obey a traffic control signal, failure to renew the registration, misuse of plates and interfering with police.

Garten, 34, was responding to a call with Kearney when Barrington fled a traffic stop, ran a red light and hit their cruiser, according to police. Garten was posthumously promoted to detective. Kearney has since been released from the hospital and is recovering from his injuries.

Barrington is now being charged with first-degree manslaughter, first-degree assault, first-degree reckless endangerment, disobeying the direction of an officer, driving under the influence and failure to yield to an emergency vehicle.

Attorney Ryan McGuigan told News 8 that Barrington’s new charges are the result of further investigation into the collision.

“Initially, after the crash, they charged this young man with what they could charge with him from what they saw on-site,” McGuigan said.

McGuigan said Barrington could face up to 50 years in prison but he will likely be looking at 20 years behind bars.

Barrington remains in custody with a bond set at $1 million.

This is a developing story. Check back for updates.