UPDATE: Family, friends ID teen struck, killed by off-duty trooper, reports say

WESTFIELD -- A 13-year-old girl was struck and killed Saturday night by an off-duty State Trooper driving his police car, authorities said Sunday.

Acting Union County Prosecutor Grace H. Park said that at approximately 8:30 p.m. Saturday, Westfield police responded to the 1800 block of Central Avenue and found the girl there. She was pronounced dead at the scene, Park said.

Friends said the teen was a freshman at Westfield High School and was part of a group of students on a scavenger hunt when she was struck.

Authorities have not announced any charges against the trooper, and he remained at the scene.

Central Avenue is a heavily trafficked thoroughfare that stretches from the parkway entrance in Clark through Westfield, ending in its downtown. The speed limit changes from 25 mph in Clark to 35 mph in Westfield.

Park said the investigation into the incident is ongoing and is being conducted with the Union County Sheriff's Office Crime Scene Unit, Union County Police Department, and Westfield Police.

Authorities did not provide any further information about the incident or give the identification of the victim or the trooper.

Anyone with information about this matter is being urged to contact Prosecutor's Office Sgt. Jose Vendas at 908-358-3048 or Westfield Police Lt. Jason McErlean at 908-789-6068.

Jessica Remo may be reached at jremo@njadvancemedia.com. Follow her on Twitter @JessicaRemoNJ. Find NJ.com on Facebook.