Video of SC police shooting inflames debate.

Byline: Bruce Smith and Jeffrey Collins

NORTH CHARLESTON, S.C. -- A young man whose cellphone video put a South Carolina police officer in jail on a murder charge said Wednesday that he gave the recording to the dead man's family because if it was his relative who was killed, he ''would have liked to know the truth.''

Feidin Santana told NBC News that while walking to work, he noticed Officer Michael Thomas Slager controlling Walter Lamer Scott on the ground, and began recording when he heard the sound of a Taser. ''Mr. Scott was trying just to get away from the Taser,'' Santana said.

Slager initially claimed he fired in self-defense after the suspect he had pulled over for a broken brake light grabbed his Taser. Santana's recording documented a different scenario. It begins at a moment when both men standing, as Scott pulls away from the officer and an object appearing to be a stun gun falls to the ground, trailing wires. As the unarmed man runs away, Slager then pulls out his Glock pistol and fires eight times at the back of the 50-year-old man, until he crumples to the ground about 30 feet away.

After the video was made public Tuesday by a lawyer for the dead man's family, Slager, 33, was swiftly charged with murder and fired, and a judge ordered him jailed without bond on the charge that could carry a sentence of 30 years to life in prison.

But that did little to quell the outrage of an angry crowd at North Charleston's City Hall, where the mayor and police chief were shouted down with calls of ''no justice, no peace.''

Not once in the moments recorded by Santana can the officer be heard yelling ''stop'' or telling the man to surrender. Moments after handcuffing the dying man face-down on the ground, Slager walks back to pick up what appears to be the Taser, then return and drop it at Scott's feet as another officer arrives to check the dying man's condition. Then he picks it up again after exchanging words with the other officer.

The video changed everything, authorities and advocates said Wednesday.

''What if there was no video? What if there was no witness, or 'hero' as I call him, to come forward?'' the Scott family's lawyer, L. Chris Stewart, told The Associated Press. ''We didn't know he existed. He came out the blue.''

Mayor Keith Summey announced that he's ordering 150 more body cameras so that every uniformed officer on the street will wear one, a key demand of the Black Lives Matter movement that is growing nationwide. For his...