She wasn't herself that night.

See Christina Aguilera's Mugshot

Christina Aguilera's bleary-eyed mugshot for her public drunkenness bust hit the web via E! News late Tuesday.
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The "Not Myself Tonight" singer, 30, was taken into custody "for her own protection," L.A. County Sheriff's Office spokesperson Steve Whitmore told UsMagazine.com. Aguilera was a passenger in a car driven by beau Matthew Rutler, who was pulled over by cops in West Hollywood and arrested for driving under the influence.
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The couple were "cooperative" during their arrest, Sgt. Michael Thomas of West Hollywood Sheriff's Department told Us. Aguilera, who was released around 7:30 a.m. Tuesday, will not be prosecuted.
"It is a public welfare issue. She was incapacitated and not able to take care of herself," spokesperson Whitmore explained.
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"She's really spiraling," an Aguilera pal told Us of the star's hard-partying ways. "I would be shocked if she's not in rehab in the next month or two."

US Magazine