A native of Minneapolis, Minnesota, Behr got an early start in performing. He was only 5 years old when he appeared in his first play. He continued to perform and enjoy the challenges of acting throughout his school years.
Directly after graduating from high school, Behr was soon guest-starring on such shows as Buffy the Vampire Slayer, 7th Heaven, Push and played Chris Wolfe on Dawson’s Creek.
On the big screen, Behr appeared in Pleasantville (1998), The Shipping News (2001), Happily Even After (2004), and starred in Rites of Passage, which debuted at the 1999 Palm Springs Film Festival and won best picture at the Santa Monica Film Festival. He is well known as one of the leads on the sci-fi series Roswell.