Justin Bieber isn't the only celebrity to crack a smile for his mug shot after an arrest. Plenty of stars have smiled, grinned or offered a sly grin while in custody.
The fact that most of these celebs were under the influence of some sort of substance when arrested could explain why they were smiling during a situation that isn't exactly funny. Or it could be the fact that they are trained to smile when the camera is on them, since it's part of their job to be the subject photos; it's the nature of the celeb beast.
Mug shots display celebs as they are -- there's no glam squad or team of handlers touching up their skin or covering blemishes. It's our fave pop stars, actors and actresses, warts and all.
The Biebs -- grinning and in need of some acne cream, since he looked to be suffering from a breakout. He was arrested for DUI while drag racing in January 2013. No mug shot matches The Biebs in terms of smile width. He looked like he would on any red carpet with that goofy grin. Maybe it was the weed. Or the beer. Or the pills.
Bruno Mars aka Peter Hernandez flashed that charming smile in his September 2010 mug shot. He was arrested in Las Vegas for possession of cocaine. He could have used an oil blotting sheet. But he was still smiling like he was posing for his driver's license.
Back in December 2006, stylish socialite Nicole Richie flashed a bit of a smirk (and dark hair!) in her mug shot. She was DUI in California, driving the wrong way on a freeway. Yikes. Nuttin' to smile about.
Lindsay Lohan has many a mug shot, but her July 2010 snap found her looking overly faux tanned. She was more orange that her prison-issue shirt.
Actor Mel Gibson was driving drunk in July 2006. Upon being pulled over, he let loose and ranted and raved to cops. He still managed a smirk in his mug shot. That curly-cue in the front is distracting.
Okay, so DJ Samantha Ronson, the ex-GF of Lindsay Lohan, wasn't exactly smiling but she was sorta giving that 'Talk to the hand' look. It's a crooked grin of sorts. She was arrested in August 2011 for DUI.
In his April 2008 mug shot, when he was arrested for battery for assaulting his wife, Vanilla Ice flashed his pearly whites and smiled. He wasn't stopping, collaborating and listening! He was all sorts of "Say Cheese!"
Actress Mischa Barton was picked up for DUI in December 2007. She posed with bedhead and a semi-smile as if on a photo shoot.
Detroit rocker Kid Rock was arrested in October 2007 for his involvement in a fight at a Waffle House. In his mug shot, he was mid-laugh with one heck of a toothy grin, looking like someone who gets in fights at Waffles House.
OJ Simpson, smiling after his robbery arrest in September 2007.
Paris Hilton's pink-slicked, pouty lipped smirk is typical of her famous red carpet pose. She flashed it June 2007.
Baby Phat's Kimora Lee Simmons, the glamazon, fashion designer and ex-wife of hip-hop mogul Russell Simmons, was glossed and grinning in her July 2004 mug shot on a drug arrest.
Reese Witherspoon, who is usually squeaky clean, was arrested in April 2013 for drunk and disorderly conduct. Her eyes were averted but an innocent grin marked her face.