Dallas Police Chief David Brown said Wednesday that a police officer accused of using excessive force last month has been fired and faces criminal charges.

Former Officer Quaitemes Williams is accused of kicking and spraying mace on Rodarick Dasean Lyles while he was handcuffed during an arrest on Jan. 27.

"The response can't be, when the suspect is defenseless and handcuffed, to kick a person in the head or even to mace a person. We have to be more professional and more disciplined than that," Brown said.

Williams, a three-year veteran of the force who was considered a rookie, also faces criminal charges of official oppression, a Class A misdemeanor.

"With this action today, we stand firm in our belief that the integrity of the DPD stands above the actions of a single officer or group or association," Brown said. "We also ask the public to view our actions as proof that we can and will police ourselves."

Lyles was on his cell phone with his girlfriend when police pulled him over, said the woman's mother, Bobbie Denwitty. She said her daughter heard the incident over the phone.

"She didn't sleep that night," she said. "It was awful."

Lyles' attorney could not be reached for comment Wednesday night.

Police chief says incident began with traffic stop

Brown said Williams became angry after he was injured in a scuffle with Lyles, who fell on Williams' arm during the altercation.

Officer Hiram Soler stopped Lyles because his plates didn't match his vehicle, police said. Soler learned that Lyles had a suspended license and had an outstanding warrant for driving without a license.

Williams and Officer Edward Cruz-Done arrived as backup. They tried to arrest Lyles, who resisted. In the scuffle, Lyles, described by Brown as a large man, fell on Williams, pinning his arm.

Brown said Williams then hit Lyles with his fist and a flashlight. Cruz-Done felt hitting Lyles with the flashlight was unnecessary and took it from Williams, Brown said.

Soler used a stun gun on Lyles, and the man was handcuffed while he was on the ground, Brown said.

Brown said the officers tried to calm Williams, whom they described as extremely angry and out of control.

Supervisor sees Williams kick, use mace on suspect

Brown said Williams sprayed mace into Lyles' face and kicked him in the head once when more backup officers arrived, distracting Cruz-Done and Soler.

Officer Rickey Upshaw, a supervisor, saw Williams kick and spray the mace as he pulled up, Brown said. He then had a verbal argument with Williams about his actions, Brown said.

The chief said Upshaw reported the incident to his supervisors, Brown said.

Sources in excessive-force cases usually wish to remain anonymous, but Upshaw, a 23-year veteran of the department, asked that his name be made public.

Brown praised Upshaw for coming forward.

"One of the things that I really want to express about Officer Upshaw's action is that we should not as a department ostracize him in any way," Brown said. "We should applaud him coming forward, him intervening. We should applaud Officer Solan, Officer Cruz-Done for pushing Officer Williams away, taking the flashlight away."

Williams charged with official oppression

Following his termination Wednesday, Williams was arrested and transported to the Dallas County Jail.

Williams was released later Wednesday. If convicted of official oppression, he faces up to a year in jail.

"Official oppression occurs when a public servant acting under the color of his office or employment intentionally subjects another to mistreatment," Brown said.

Brown said the department had also contacted the civil rights division of the FBI about the case.

Soler received a sustained allegation of entering inaccurate, false or improper information on a police report. Soler, who has been with the Dallas Police Department for almost three years, was disciplined with a 10-day suspension.

Case is latest high-profile dash-cam incident

Dallas police officers have previously come under fire for incidents captured on dashboard cameras.

In September, three Dallas officers were fired for their role in the videotaped beating of motorcyclist after a chase.

Brown changed police policy to pair rookie officers with more experienced officers.

Two years ago, the department made national headlines when an officer detained NFL player Randy Moss in a hospital parking lot while his mother-in-law was dying.

The officer in that case resigned.

Dallas police recently created a special unit to review dash-camera video.

NBC DFW's Ellen Goldberg contributed to this report.