FAIRFAX, Va. (CBSDC) — A search party has gathered at Thaiss Park in Fairfax, Va. to continue the search for a teen who has been missing since last week.

Seventeen-year-old Bryan Glenn was last seen in the parking lot of WT Woodson High School, where he is a senior, around 7 a.m. on Oct. 1. There are signs he was at a Dunkin Donuts near Fairfax Circle about an hour later, but has not been seen since.

Glenn’s father, a colonel in the U.S. Army, has organized a group of more than 400 volunteers to look for his son.

The group has fanned out in the park where Glenn’s car was discovered last week.

Police say there are no signs that the teen was abducted or that foul play is involved.

However, friends believe Glenn’s disappearance is out of character. He was planning on taking a date to Homecoming and visiting college campuses in the near future. In addition, the teen has recently been taking SAT prep classes.

Police say Glenn’s disappearance is unusual, but are not ready say the case is suspicious.