A deputy was conducting a vehicle enforcement stop on Highway 111 near El Paseo at 12:07 a.m. when his patrol unit was struck from behind by a Chrysler Intrepid. The patrol unit moved forward and hit the stopped vehicle in front.
All three vehicles received moderate damage. No one was injured.
The police unit's lights were flashing, according to police.
The driver of the Intrepid, 56-year-old Mark Angleton of Palm Desert, was arrested. Police believe alcohol played a factor in the collision.