PARIS MUGS FOR COPS -- AGAIN

PARIS HILTON just can't take a bad picture, even if it's a mug shot after being arrested in Las Vegas for cocaine possession.

Looking glam with her hair freshly coiffed, Paris smirked as police photographed her after taking the heiress into custody late Friday. Cocaine was allegedly found in her purse after a traffic stop. She was released without bail early Saturday.

At the time of her arrest, Paris was reportedly in a car with her boyfriend CY WAITS, who operates a nightclub in the Wynn Hotel. Earlier in the week Paris and Cy were at her Los Angeles home when a man, who was armed with two knives, allegedly attempted to break in.

This is Paris' third drug-related incident this summer. In July she was caught with a small amount of marijuana while visiting the French island of Corsica. Then at the World Cup in South Africa, she was allegedly caught smoking pot. Both times she was released without being charged.

Three years ago, Paris served a short amount of time in a jail after violating probation in an alcohol-related driving case.