Before his body was discovered, police responded to a report of shots fired about a mile from the scene. The passenger's side windows of the SUV were shattered.
Police say they believe Tevlin was targeted.
Nobody has been arrested in the case, but a $10,000 reward aims to lead investigators to his killer.
Authorities have released surveillance photos that show two men running in the area where the murder took place. The men may have been eyewitnesses.
Tevlin was a club lacrosse player at the University of Richmond, an honor student and talented bagpiper.
A funeral is planned for 11:00 a.m. Tuesday, July 1, at Saint Philomena's Church in Livingston. Visitation will be held Monday, June 30, from 3:00 p.m. to 9:00 p.m. in the auditorium of Seton Hall Preparatory School in West Orange.
In lieu of flowers, donations can be made in Tevlin's name to Seton Hall Prep, 120 Northfield Avenue, West Orange, NJ 07052.