Alleged Hollywood Nightclub Murderer ARRESTED [Updated w/ Mug Shot]

The person who allegedly shot and killed a man outside a Hollywood nightclub has been arrested ... TMZ has learned.

Law enforcement sources tell TMZ ... Robert Earl Thomas III was hiding at a friend's house in Las Vegas when cops entered the premises last night and placed him under arrest for murder. He surrendered without a struggle.

TMZ posted video of the shooter outside Empire nightclub when he aimed the gun and fired, killing one man and wounding another. The video clearly shows the shooter and law enforcement tells us they got a number of tips from people who saw it and that led to Thomas' capture.

Thomas is 22 years old and lives in Los Angeles.

Thomas is currently being held in a Vegas jail and prosecutors plan to extradite him to California.