Amber Guyger, the Dallas police officer who faces a manslaughter charge in the shooting death of Botham Jean, has been fired, the Police Department announced in a news release Monday.

Chief Renee Hall fired Guyger, 30, after a "very short" internal affairs investigation and hearing Monday morning, sources told WFAA. The only thing she was questioned about, according to sources, was whether or not she had been arrested for manslaughter.

The news release said the investigation concluded that Guyger "engaged in adverse conduct" when she was arrested for manslaughter for fatally shooting Jean at his South Side Flats apartment on the night of Sept. 6.

"Officer Guyger was terminated for her actions," the news release said.

The internal affairs investigation Monday was separate from an ongoing criminal investigation into the shooting. Guyger's arrest on Sept. 9 alone is reason enough for internal affairs to decide she should be fired.

The firing is a reversal in course for Hall, who last week said federal and state laws were preventing her from firing Guyger. Hall also said that an internal investigation could "potentially compromise the criminal investigation."

The Dallas Police Department general orders – the policies that officers have to follow and are governed by within the department – allow the chief to "circumvent all formal disciplinary procedures to render an immediate decision when it deems it necessary to preserve the integrity of the department.”

Hall released a statement on Friday saying an administrative hearing might hurt the investigation if Guyger was forced to give a statement to internal affairs detectives at DPD. She reiterated that on Monday.

"Those same statements if they were to get into the hands of the individuals that are conducting an investigation could impact the outcome of the investigation,” said Hall.

Experts disputed this because statements given to internal affairs are protected and can not be given to criminal investigators or the District Attorney. Guyger had already given the Texas Rangers her statement that will be used in her criminal trial

"Pursuant to their own general orders the Chief had the authority to fire her some time ago,” said Daryl Washington, who is one of the attorneys representing Jean’s family.

WFAA asked Chief Hall what changed between Friday and this morning. She said she was told that the "critical part" of the criminal investigation was over.

"As a police chief, my job is to ensure the integrity – the highest level of integrity – in this criminal investigation and that is what I did," Hall said Monday.

WFAA checked with multiple sources close to this case who say nothing changed over the weekend and, in fact, they still have a long way to go in the investigation.

Guyger, who had surrendered her badge and gun when she was put on administrative leave after the shooting, had left the department headquarters by noon Monday. Under Civil Service rules, Guyger can appeal her firing.

Guyger, a patrol officer, was hired by the Dallas Police Department in November 2013.

Lee Merrit, one of the attorneys representing Jean's family, said that Hall informed him and Jean's parents on Sunday afternoon that she would be firing Guyger.

Merritt said Hall explained that a "premature" firing could have compromised the criminal investigation.

Jean's family "expressed satisfaction" in Hall's explanation and saw Guyger's firing as "an initial victory," Merritt said.

"The family is happy that there is some since that there is justice but hoped it would have happened a week ago or so,” said Washington.

Guyger's attorney, Robert L. Rogers, released the following statement:

What happened on September 6th was a tragic mistake and words can never express our sorrow for the pain being suffered by those who knew and loved Botham Jean. Amber Guyger is completely devastated by what happened. Unfortunately, today Chief Hall bowed to pressure from anti-police groups and took action before all of the facts had been gathered and due process was afforded. That’s not the way our system of justice should work. It is important for all parties and the integrity of the justice system that a full and fair investigation be allowed to reach its conclusion before decisions such as this are made.

Dallas Mayor Mike Rawlings said he agreed that Guyger's firing was the "right decision in the interest of justice" for Jean.

Accounts of the shooting

Guyger mistook Jean's the unit for her own, according to an arrest warrant affidavit.

Guyger, who lived in the apartment below Jean, had just gotten off duty and parked on the wrong floor in the parking garage at the apartments, the affidavit said.

The two accounts of the shooting offered slightly different details.

The arrest warrant affidavit – written by Texas Rangers, who took over the investigation – said Guyger found Jean's front door "slightly ajar," and then opened it by pushing a key into the door. When she opened the door fully, Guyger saw a "large silhouette" across the room and began giving commands, which Jean "ignored," the affidavit said.

The search warrant affidavit – written by a Dallas police detective before the Rangers were handed the case – also says that Jean's door was open when Guyger inserted a key but that Jean "confronted the officer at the door." A neighbor told police that he "heard an exchange of words, immediately followed by at least two gunshots," the search warrant affidavit said.

Neither affidavit detailed how close, specifically, Guyger and Jean were to each other during the encounter.

Protests and backlash

Several protests have been held, calling for Guyger's firing and for her charge to be upgraded to murder. A protest by the Next Generation Action Network was still scheduled to be held at the Dallas Police Department on Monday night.

On Sept. 14, protesters rallied from the Dallas Police Department, near the apartments where Guyger shot Jean, to downtown. Two days later, protesters wheeled a coffin to the entrance of AT&T Stadium before the Cowboys-Giants game as part of a symbolic funeral procession for Jean.

The case will be presented to a grand jury, which will decide whether to indict Guyger for manslaughter or a different charge.

District Attorney Faith Johnson has said that her office "will make sure that justice is done in this case."

“My commitment is to make sure that there’s going to always be equal justice in this county, and that’s my commitment to this community," Johnson said.

Jean laid to rest in St. Lucia

The news of Guyger's firing came just hours before Jean's funeral was scheduled to be held in his native St. Lucia.

Jean, who came to the United States to attend Harding University in Searcy, Ark., was working as a risk assurance associate at PriceWaterhouse Coopers in Dallas.

A service for Jean was held in Dallas on Sept. 13 at Greenville Avenue Church of Christ, where more than 1,500 people gathered and listened to stories about Jean's life.

"To know Botham was to love Botham,” Michael Griffin, of Singing Hills Church of Christ, told the crowd. “He was the light in a dark room.”

This is a developing story. Check back for more details.