"I ask God for forgiveness, and I hate myself every single day," Amber Guyger said.

A former Texas policewoman was convicted of murder Tuesday for shooting dead a neighbor in his own home in what her lawyer said was a "tragic mistake."

The case sparked outrage as it became a flashpoint on police violence and racial bias because Amber Guyger is white, while her victim was black.

Guyger, who worked in Dallas, claimed after the September 6, 2018 shooting that she mistakenly believed she had returned to her own apartment and that Botham Jean, 26, was an intruder.

In fact, the 31-year-old -- a police officer for four years until her sacking following the shooting -- had entered Jean's unlocked apartment located in the same building but one floor above hers.

"We the jury unanimously find the defendant, Amber Guyger, guilty of murder as charged in the indictment," the jury foreman announced in images shown on cable news.

After the verdict was read, Jean's mother, Allison Jean, stood and looked upward as she celebrated the jury's decision, raising her arms high and wide. His sister sobbed.

"God is good. Trust him," Allison Jean said as she left the courtroom, the Dallas Morning News reported.

The jury retired Monday, deliberating for five hours.

Guyger, who was off duty after a nearly 14-hour shift, lived in apartment 1378 on the third floor, while Jean lived in apartment 1478 directly above her.

"She knows she's made a tragic mistake, but it's not out of evil," Guyger's lawyer, Robert Rogers, told the court as the trial opened, describing it as human error and an act of self-defense.

Guyger sobbed as she took the stand last week.

Appeals for justice

"I ask God for forgiveness, and I hate myself every single day," she said, voice trembling.

"I wish he was the one with the gun who had killed me. I never wanted to take an innocent person's life," she added.

After hearing the verdict, Guyger stood as the jury filed out of the courtroom and then sank into her chair.

Prosecutor Jason Hermus said Jean, a native of the Caribbean island of St. Lucia who worked for an accounting firm, "paid the ultimate price" for her errors.

"She walks past 16 different apartments and fails to register the number four on any one of them," Hermus said during the testimony phase of the trial last week.

During the trial prosecutors played Guyger's frantic 911 call, in which she repeatedly tells a dispatcher she is in the wrong apartment.

Jean's parents were in court when bodycam footage from responding officers showed them trying to save his life as he lay bleeding, US media reported.

The shooting and its aftermath sparked demonstrations and appeals for justice in a nation where white police officers who shoot people of color often go free. Demonstrators rallied outside the Dallas police headquarters and city hall.

Jurors were given the option of finding Guyger guilty of the lesser offense of manslaughter but a grand jury indicted her on the more serious charge of murder following the protests.

She faces up to life in prison when she is sentenced later Tuesday.