The city of Dallas has been dismissed from a wrongful death lawsuit submitted by the family of a man who was killed in his own home by an off-duty police officer, a federal judge has ruled.
Relatives of Botham Jean filed the lawsuit a month after he was killed by Amber Guyger in his South Side Flats apartment while he was watching television.
Guyger was coming off a 13-hour shift as a Dallas police officer on Sept. 6, 2018, when she said she mistook Jean's apartment for her own and thought he was an intruder. That's when she opened fire on him.
Jean, 26, immigrated to the United States from St. Lucia for college and, before his murder, was an accountant at PricewaterhouseCoopers.
A jury convicted Guyger in October for Jean's murder. Jean's younger brother stunned viewers of the televised two-week trial when he hugged and forgave Guyger before a judge imposed a 10-year sentence.
In the federal civil lawsuit, Jean's mother, father and sister -- all named plaintiffs -- charged that Guyger and the city of Dallas were equally responsible for the murder.
The city, which employs the police department, "implement the necessary policies and the (de facto) implementation of unconstitutional policies, caused Jean to experience an unwarranted and excruciating physical and mental anguish before his ultimate death," according to the lawsuit.
Guyger, 31, was fired from her job after an internal affairs investigation concluded she "engaged in adverse conduct," officials announced in September 2018.
The city filed a motion in November 2018 requesting to be dismissed from the lawsuit, citing Jean's family's attorneys' -- Lee Merritt, Ben Crump and Daryl Washington -- "failure to state a claim" against them, according to the online records. The civil case proceeded simultaneously with the criminal matter until the murder trial commenced in September 2019.
Federal court chief Judge Barbara Lynn ruled on Dec. 23 in favor of the city of Dallas and dismissed them from the lawsuit "with prejudice," according to the judge's decision.
The Jean family's legal team filed a notice of appeal on Friday, according to the documents obtained by ABC News.
"Amber Guyger was off duty at the time, but it has always been our argument that when she took Botham Jean's life, she was on duty," said Washington. "She testified that she responded to what she thought was a crime and whenever an officer says they respond to a crime, they are considered back on duty...the Supreme Court has ruled on this before."
Guyger remains the sole defendant on the lawsuit. She is currently housed in Mountain View Correctional Facility in Gatesville and will be eligible for parole in 2024, according to online records.
Amy L. Messer, the senior assistant city attorney for Dallas, declined to comment to ABC News on the dismissal.
In an interview with The Dallas Morning News, Jean's mother said she has "no hatred toward" Guyger and "It's time to focus on me and heal in the best way I know how."
Guyger's lawyer, Mark Goldstucker, did immediately respond to request for comment.