Image copyright Kaufman County Jail/ Botham Shem Jean/Facebook

A Dallas police officer who fatally shot a black man inside his own flat, saying she confused it for her own home, has been fired.

Amber Guyger "engaged in adverse conduct when she was arrested for manslaughter", police said in a press release on Monday.

Botham Shem Jean died on 6 September, after Ms Guyger entered his home in the building where they both lived.

Ms Guyger, 30, is currently out on bail, pending a criminal trial.

Dallas Police Chief U Renee Hall terminated her employment during a hearing on Monday, police said, adding that she has the right to appeal.

She had been on administrative leave, as activists called for her immediate firing.

Court records show Ms Guyger had just finished a 15-hour shift when she parked in the wrong garage before making what was apparently a tragic error.

Ms Guyger entered the apartment after finding the door ajar, and saw Mr Jean, 26, in the darkness as a "large silhouette", according to the arrest warrant affidavit.

She said she gave verbal commands that he ignored, so she fired her weapon.

The arrest warrant affidavit, written by the Texas Rangers, differs slightly from the search warrant affidavit by Dallas police, local media report.

The search warrant statement says Mr Jean "confronted the officer at the door".

Neither document specifically states how close Ms Guyger was to Mr Jean when she shot him.

Police have been criticised for not immediately identifying the officer that killed Mr Jean, whom the Dallas mayor called a "model citizen".

After revealing that they had found marijuana at his home, a lawyer for his family accused the police force of trying to "smear" his reputation.

S Lee Merritt, a lawyer for the Jean family, told reporters on Monday that they viewed Ms Guyger's firing as a "victory", US media reported.

"The Jean family expressed satisfaction in this explanation and in Guyger's termination. We see it as an initial victory."

Mr Merritt's statement also said that they were informed of Chief Hall's plans to fire Ms Guyger on Sunday. Chief Hall said firing the officer too early on in the investigation could have affected the criminal case against her.

The Mayor of Dallas, Mike Rawlings, also weighed in on Ms Guyger's firing.

"I agree that this is right decision in the interest of justice for Botham Jean and the citizens of Dallas," Mr Rawlings said in a statement.

"The swift termination of any officer who engages in misconduct that leads to the loss of innocent life is essential if the Dallas Police Department is to gain and maintain the public trust."

Mr Jean grew up on the Caribbean island of St Lucia and went on to work for the professional services giant PricewaterhouseCoopers.

A state funeral for Mr Jean was planned for Monday in St Lucia.