Bieber was arrested on Jan. 23 on charges of DUI, resisting arrest and having an expired driver's license. Police said the 19-year-old admitted to using both pot and Xanax at the time of his arrest.
The young pop star has pleaded not guilty to charges. A previous police report found that breath tests placed Bieber's blood-alcohol content below the .02 level considered intoxicated for under-21 drivers.
Bieber is also facing an assault charge in Toronto for allegedly hitting a limousine driver several times in the back of the head in an incident last month. He surrendered to authorities Wednesday night and is scheduled to appear in court on March 10.
Toronto's infamous Mayor Rob Ford, who admitted smoking crack while in a drunken stupor, is coming to Bieber's defense. During a radio talk show, when the host called Bieber "Canada's worst export," Ford said "Well, you know what, he's a young guy. At 19 years old, I wish I was as successful as he was."
Bieber remains under investigation for felony vandalism in Calabasas. He's accused of egging his neighbor's home, causing thousands of dollars in damage.
Bieber just settled a lawsuit with a former bodyguard who accused the singer of assaulting him backstage before one of his concerts.
The Associated Press contributed to this report.