A Dallas police officer accused of fatally shooting her neighbor inside his apartment in early September has been fired after an internal investigation determined she "engaged in adverse conduct".

Amber Renee Guyger - Kaufman County Sheriff's Office.jpg

The Dallas Morning News reports that former patrol office Amber Guyger, 30, was arrested for manslaughter after she allegedly gunned down 26-year-old Botham Shem Jean on the night of September 6. Guyger says she parked on the wrong floor of her apartment building's parking garage and entered Jean's apartment, believing it to be her own. She told investigators she mistook Jean for a burglar when she allegedly shot him.

Jean's family, witnesses from the apartment complex, and an attorney have questioned Guyger's story and demanded she be fired. Dallas PD Chief Renee Hall initially said she could not fire Guyger due to state and federal laws which she did not specifically cite when asked about her decision.

On Monday, Chief Hall announced that Internal Affairs had completed an investigation and given the clear to fire Guyger for engaging in what investigators called "adverse conduct".

According to a report from WFAA, Dallas officers can be fired by Internal Affairs if they are arrested for a crime or do anything to discredit their department. Chief Hall was reportedly concerned about interfering in the criminal investigation surrounding Guyger and was awaiting the results of an Internal Affairs hearing.

Three days after the shooting, Guyger was charged with manslaughter and bonded out of jail for $300,000. Depending on the results of the criminal investigation, she may face further charges.