See Christina Aguilera's Mugshot

Credit: E! NEWS

She wasn't herself that night.

Christina Aguilera's bleary-eyed mugshot for her public drunkenness bust hit the web via E! News late Tuesday.

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.

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.

"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."