Samantha Ronson's D.U.I. mug shot revealed; Rumors of alcoholism swirl

Samantha Ronson, D.J. and ex-girlfriend of Lindsay Lohan, was arrested at about 10:30 a.m. on Monday morning as she drove back to Los Angeles from Las Vegas, where she had D.J.'ed a party the night before.

Now, TMZ has uncovered her mugshot. That's one heck of a scowl!

The site, which was first to report the DUI, reports that her blood alcohol level at the time of her arrest was over twice the legal limit. They also report that her friends are unsurprised by the arrest and that Ronson has been struggling with alcohol lately -- "boozing more than ever" and "hitting the nightclubs A LOT harder than she used to."

Even Lohan, who recently completed treatment at the Betty Ford Center for substance abuse problems, has avoided contact with Ronson because she feels she's a negative infuence.