Paris/Bruno D.A. Allegedly Scored Coke 4X a Week

3/21/2011 1:46 PM PDT

Paris/Bruno D.A. David Schubert Allegedly Scored Coke 4X a Week!

The deputy D.A. who prosecuted Paris Hilton and Bruno Mars scored coke 3 to 4 times a week in the crack den of Las Vegas ... this according to the police report obtained by TMZ, and we've learned he's been locked out of his office and is about to get fired.

David Schubert, who was busted Saturday night, had gone to a notorious area of Vegas Saturday night.  Schubert, who was driving a BMW, stopped and cops observed a male get inside his car.

The two began driving and cops were suspicious, after the passenger got out of the car, went into a an apartment complex and came back out.  When Schubert allegedly committed a traffic violation, cops made their move and stopped the vehicle.  The passenger got out and ran, and was subdued after a foot chase.

The passenger then snitched Schubert out, telling cops Schubert would come by 3 to 4 times a week and use him to purchase $40 worth of cocaine at a time.  The passenger says Schubert would call periodically to ask if anyone was selling narcotics.

Mind you ... this was allegedly going down at the same time Schubert was prosecuting Paris and Bruno.

Cops observed a "white, rocklike substance" in the car and it tested positive for cocaine.

David Roger, the Clark County District Attorney, tells TMZ, "We are very disappointed.  He [Schubert] has betrayed the trust that was placed in him.  He's been locked out of his office, placed on suspension and is in the process of being terminated."