Johnson captured the video on a body camera that he purchased with his own money.
"He was running after a suspect. The suspect fell after he was Tased. He Tased him twice, the person said he Tased him numerous times, so this showed right there immediately that didn't happen," said Assistant Chief Jason Dusterhoft with the Austin Police Department.
Police said the use of body cameras could speed up investigations, both internal and external.
"If you look at it from the officer's perspective this is going to be a great tool for them. Number one for training, but also it's kind of, it's going to be kind of a third party witness to say this is exactly what the officer did," said Dusterhoft.
Charley Wilkison, executive director of the Combined Law Enforcement Associations of Texas said in many cases body cameras could end up helping officers more than suspects.
"That's going to be the uncomfortable truth, that all the folks screaming for cameras are going to come to the realization that officers are acting in the public's interest, they're following their training and police departments are training officers the right way," said Wilkison.
Unfortunately, body cameras may not be the end all say all for every investigation.
"If something else is wrong in the room where a suspect can't be seen, the wrong person is seen or other issues like that, and then the cameras won't be very good. In fact, they'll be a problem from time to time," said Wilkison.
Austin police officials said like it or not, officers can expect body cameras in the near future.
"This is something we feel that anyone doing any type of law enforcement duties, whether they're in uniform, should have one of these cameras," said Dusterhoft.
The Austin Police Department would like to have 1,000 officers equipped with body cameras within the next two years. The total cost for cameras, software and server space is about $5.5 million.