The bystander who recorded video that appears to show a white police officer shooting an unarmed black man in the back in South Carolina said there was a struggle between the two men before the deadly shooting, but the officer had control of the situation before he opened fire.

In an exclusive interview with “NBC Nightly News” anchor Lester Holt on Wednesday, Feidin Santana said he started recording after he heard a Taser being deployed.

“I remember the police had control of the situation,” Santana said. “He had control of Scott. And Scott was trying just to get away from the Taser.”

Officer Michael Slager was arrested and charged with murder Tuesday for the fatal shooting of Walter Scott after a traffic stop on Saturday. The video appears to show Slager shooting Scott in the back as he was running away from the officer.

“As you can see in the video, the police officer just shot him in the back,” Santana said. “I knew right away, I had something on my hands.”

Santana turned the video over to Scott’s family.

North Charleston Mayor Keith Summey announced Wednesday that Slager was fired. He also ordered body cameras for the police force. Every officer on the street will wear one after a policy is established and the force is trained, Summey said.

This article originally appeared at NBCNews.com