An off-duty security guard reported that he was sitting on a bench on the platform, watching videos on his cell phone, with his green & black backpack on the bench beside him. He saw the pack move, looked up and saw a male suspect carrying it away. The suspect was described as a black male, 6' tall, with a skinny build, wearing a gray hooded sweatshirt. The suspect fled from the station via the 14th Street exit. An area check for the suspect was unsuccessful. The victim reported that his .40 caliber Beretta pistol was inside the backpack when it was stolen. Oakland PD was advised of the theft.