The incident happened around 5:45pm Saturday along the feeder road of the Eastex Freeway at Collingsworth.
"I just seen the police shoot him and he fell," said a woman who was working the drive-thru at a nearby Burger King. She does not want to be identified and says she witnessed the shooting from a distance.
"The police was not in danger to kill that man. I'm sorry," she added.
She didn't see what lead to the shooting.
Police say the officer initiated contact after seeing the man damaging a street sign. As soon as he got out of the patrol car, he realized the man was agitated. An HPD spokesperson says the man was cussing, seemed to be on drugs and refused to stop advancing toward the officer. The officer, identified as K. Levi, tased him twice in the chest -- but it didn't stop him.
"He said it was probably in the proximity of three to four feet. That the suspect got that close to him," said HPD Public Affairs Officer John Cannon.
Investigators say the officer told them he was retreating into traffic when he opened fire.
"He says he had no choice and was protecting his own life," Cannon said.
Family at the scene identified the man as Peter Matthew Gaines. They tell Eyewitness News he just celebrated his birthday.
Police say he was not armed which has some asking if the officer could have done anything else before using lethal force.
"They didn't have to do what they did to him," said Gaines' friend Tracy Turner.
The officer has been with HPD for four years and has never discharged his duty weapon on the job. He will be placed now on three days of administrative leave, per protocol.
Both the suspect and officer are African-American.