From WENN.com

The Private Practice star took to the red carpet with his wife Idina Menzel at the Los Angeles event, and the pair headed home after the ceremony ended.

Diggs was in the property when he came face to face with a stranger, who ran away after he was confronted by the actor.

The star gave chase and managed to catch the man, who he held until police arrived on the scene, according to TMZ.com.