Photo: LA County Sheriff's Office
Paris Hilton imprisoned :

June 4, 2007
Paris was sentenced to 23 days in prison for violating probation after she was caught driving on January 15, 2007 with a license suspended as a result of a prior DUI arrest. Her booking number was 9818783.
Source: The Times (London), 6/5/2007

Photo: Duncan Rawlinson (2007 flickr)
Paris Hilton arrested for drunk driving in Hollywood:

September 7, 2006
On September 7, 2006, two LAPD motorcycle officers pulled Hilton over at 12:30 a.m. after seeing her Mercedes moving erratically, and arrested her after she failed a sobriety test.
Source: Los Angeles Times, 9/8/2006

Mug Shot (Photo: Glendale Police Dept')
Nicole Richie arrested for drunk driving:

December 11, 2006
On December 11, 2006, Nicole Richie was arrested driving under the influence after being spotted driving the east in the westbound lanes of traveling east in the westbound lanes of the 134 Freeway in Burbank, California.
Source: Los Angeles Times, 12/12/2006

Paris In Venice Beach (Photo: Duncan Rawlinson (2007 flickr))
Paris Hilton pulled over in a $190,000-dollar Bentley Continental GTC while driving with suspended license:

January 15, 2007

Source: Agence France Presse, 4/4/2007