"Scott was trying to just get away from the Taser"

Warning: The video above contains graphic content.

For the first time, the man who videotaped the white South Carolina police officer charged with murdering Walter Scott, a black man, is speaking out, reports CBS News correspondent Vicente Arenas.

"I remember the police had control of the situation. He had control of Scott. And Scott was trying to just get away from the Taser," Feidin Santana said on NBC News.

The North Charleston Police fired Officer Michael Slager Wednesday, the day after graphic cellphone video surfaced if him fatally shooting Scott in the back after what began as a routine traffic stop.

" ... I think that (Slager) made a bad decision. And you pay for your decisions in this life, I think," Santana said.

Slager remains locked up, held without bail, but he isn't the only one authorities are looking at for answers. According to police, at least seven officers arrived at the scene within minutes of the shooting, and their conduct is also being investigated.

Santana said he considered deleting the video from his phone and leaving town.

"I felt that my life, with this information, might be in danger," Santana said.

Police say dash cam video of the traffic stop that led to the incident could be released as early as Thursday.

The city's mayor has also ordered more than 250 body cameras -- enough for every officer on the force.

Even with Santana's video, authorities have not able to determine whether anyone had performed CPR on Scott, as stated in the police report.

"Not every officer is CPR certified," North Charleston Mayor Keith Summey said.

Dozens of demonstrators took to the streets in North Charleston Wednesday to vent their frustration.

Protesters also shouted throughout a news conference where even the city's police chief admitted he found the incident disturbing. "I have watched the video and I was sickened by what I saw," Eddie Driggers said.

Slager's new attorney told "CBS This Morning": "As we focus in on the facts, we will probably have more to say, but it is far too early for us to be saying what we think."

Slager, a Coast Guard veteran, had two complaints against him in his five years on the police force, including a 2013 incident involving a Taser for which he was cleared of any wrongdoing.