DALLAS — A white former Dallas police officer who shot her black unarmed neighbor to death after, she said, mistaking his apartment for her own, was convicted of murder Tuesday in a verdict that prompted tears of relief from his family and chants of “Black Lives Matter” from a crowd outside the courtroom.

The same jury that found Amber Guyger guilty in the September 2018 death of her upstairs neighbor, Botham Jean, will consider her fate after hearing additional testimony that started Tuesday afternoon. She could be sentenced from five to 99 years in prison under Texas law.

The jury took a matter of hours to convict Guyger, 31, after six days of testimony.

Cheers erupted in the courthouse as the verdict was announced, and someone yelled “Thank you, Jesus!” In the hallway outside the courtroom, a crowd celebrated and chanted “black lives matter.” When the prosecutors walked into the hall, they broke into cheers.

After the verdict was read, Guyger sat alone, weeping, at the defense table.

Jean’s friends and family later testified to explain how his death has affected them. First on the stand was Allison Jean, who said her son was killed just before he was due to turn 27.

“My life has not been the same. It’s just been like a roller coaster. I can’t sleep, I cannot eat. It’s just been the most terrible time for me,” she said.

Botham Jean’s sister, Allisa Findley, told the jury that she and her mother cry a lot, her formerly “bubbly” younger brother has retreated as if into a shell, and that her father is “not the same.”

“It’s like the light behind his eyes is off,” Findley said.

She said her children are now afraid of police.

Prosecutors also submitted text messages — accepted as evidence over defense objections — that indicated Guyger lacks sensitivity toward black people.

In one, she suggests participants at a Martin Luther King Jr. Day parade in Dallas could be persuaded to go home with the use of physical violence and pepper spray. In a message sent to Guyger’s phone, the messenger suggests she would like a German shepherd because the dog is racist. Guyger declares that she hates “everything and everyone but y’all.”

Guyger’s defense attorneys can argue that she deserves a light sentence because she acted out of sudden fear and confusion. The judge is expected to provide guidance on sentencing law.

It is unclear how long the punishment phase of the trial will last. Testimony will resume Wednesday.

The basic facts of the unusual shooting were not in dispute throughout the trial. After a long shift at work and still in uniform, Guyger walked up to Jean’s apartment — which was on the fourth floor, directly above hers on the third — and found the door unlocked. Thinking the apartment was her own, she drew her service weapon and entered.

Jean, an accountant from the Caribbean island nation of St. Lucia, had been eating a bowl of ice cream when Guyger entered his home and shot him.

The shooting drew widespread attention because of the strange circumstances and because it was one in a string of shootings of unarmed black men by white police officers.

“This is a huge victory, not only for the family of Botham Jean, but this is a victory for black people in America,” said Lee Merritt, one of the lawyers for Jean’s family. “It’s a signal that the tide is going to change here. Police officers are going to be held accountable for their actions, and we believe that will begin to change policing culture around the world.”

The jury that convicted Guyger was largely made up of women and people of color.

Attorney Ben Crump, also representing the family, credited the makeup of the jury for Tuesday’s conviction, and said he expects them to deliver a weighty sentence.

“I look at the diversity of this jury,” he said. “They will see past all the technical, intellectual justifications for an unjustifiable killing. And I believe they will do the right thing.”

Dallas Police Association President Mike Mata declined to comment Tuesday, saying Guyger’s lawyers asked him to wait until after sentencing. The group, which represents city police officers, has paid for Guyger’s legal defense and security.

The verdict may have defused tensions that began simmering Monday when jurors were told they could consider whether Guyger had a right to use deadly force under a Texas law known as the castle doctrine — even though she wasn’t in her own home.