It has been more than a year since a former teacher at Bishop O'Connell High School went missing, and still, there is no sign of him.

Thomas L. Duesterhaus, who would now be 39 years old, left his home in Arlington on June 17, 2011, in a 1999 blue Buick LeSabre and never returned. His case remains under investigation.

Duesterhaus had been fired from his job as an English teacher just days before his disappearance. His father, Rich Duesterhaus, told The Washington Examiner that his son would have been particularly distraught from being fired, as teaching and writing were his passions.

His car and other personal items were reportedly found in a Virginia Beach, Va., parking lot in the days after his disappearance. Duesterhaus was said to have been starting a four-day retreat there.

Rich Duesterhaus told The Examiner that there have been a few reported sightings, including one from a stranger who said he saw Thomas Duesterhaus driving on the highway, but they were nothing that ever panned out.

Thomas Duesterhaus was a member of the Young Apostles, a group that lives together and serves youth in the Catholic Church.

The group asks anyone with information on the case to contact their director, Father Jack Peterson, at 703-556-0914 or at Father.Jack@marymount.edu. They can also contact Thomas Duesterhaus' father at rich@duesterhaus.net or Fairfax County Police Department Detective Chris Flanagan at 703-246-7860.

Thomas Duesterhaus is white, 6-foot-3, with dirty blond hair and green eyes. He typically wears glasses and was last seen wearing dark slacks and a white short-sleeve shirt.