The video was captured on the evening of November 25, when prosecutors say 19-year-old Trevonnte Brown got on a downtown to West Seattle bus.
The video shows a man -- who police identify as Brown -- pull out a handgun and rob two passengers of their cell phones. As he walks toward the front of the bus, the robber stops and points his gun in the face of a seated passenger.
That passenger stands up and lunges at the gunman, which sparks a melee that ends with several other passengers holding the robber on the ground.
Chris Briggs was one of the first passengers robbed. He was on his way home when Brown got on the bus, and he said he immediately noticed something off about him.
"We noticed that his face was kind of covered and he was wearing a hoodie, too, so you couldn't quite tell what was going on," Briggs said.
Briggs said the robber then pointed a gun at him and told him to hand over his phone. Briggs initially said no, put quickly thought better of it.
"He jabbed me a little harder and said, 'Don't make this any harder than it has to be,'" he said.
Moments later, when a passenger was scuffling with Brown, Briggs and others jumped in to help.
"Then me and a couple other guys all just kind of jumped at the same time to kind of tackle him," he said.
Brown, a recent graduate of Franklin High School with no criminal history, was arrested and is being held on $350,000 bail.
Prosecutors called Brown an "extreme danger to the public" and charged him with three counts of robbery and one count of attempted robbery. He pleaded not guilty to all counts.
Brown could face more than 15 years in prison if convicted.
A case setting hearing is scheduled for December 30 at the King County Courthouse.