Updated at 4:10 p.m.: Revised to include that the mayor declined to comment.

The parents of 26-year-old Botham Jean plan to sue the city of Dallas and the former Dallas police officer who fatally shot him in his own apartment earlier this month.

Attorney Lee Merritt said Allison and Bertrum Jean plan to file a federal lawsuit claiming Amber Guyger used excessive force.

The city will be named as a defendant because Guyger was operating "under the color of state authority" even though she was off the clock, Merritt said.

"She is in uniform, she was wearing a badge, she purports to give commands, which he allegedly failed to comply to," he said. "Clocking in or clocking out has no bearing on that analysis."

Merritt said he didn't know when the lawsuit would be filed.

Through a spokesman, the mayor declined to comment on the lawsuit.

Legal experts have said Dallas could be held liable for Jean's death if lawyers can convince a court that Guyger was acting in the scope of her employment when she killed Jean.

Allison and Bertrum Jean pose for a portrait as they hold a photo of their son Botham Shem Jean at their home in Castries, St. Lucia on Tuesday, September 25, 2018. Botham Jean was shot and killed in his apartment by off-duty Dallas police Officer Amber Guyger. (Vernon Bryant / Staff Photographer)

The Dallas Police Department fired Guyger on Monday, more than two weeks after the Sept. 6 shooting at the South Side Flats apartment complex in the Cedars. She was charged with manslaughter three days after the shooting and turned herself in at the Kaufman County Jail. She posted bail within an hour and is free awaiting trial.

Guyger told investigators she had unknowingly parked on the wrong floor of the parking garage and then walked into the apartment directly above hers thinking it was her own.

She said she saw a silhouette in the apartment and mistook Jean for a burglar. She fired her service weapon twice, striking him in the torso.

Before the shooting, Jean was watching football in his apartment. He had been eating cereal and texting a friend.

Jean's family and their attorneys have said they don't believe the former officer's version of events, pointing to differences in Guyger's account of the shooting according to police documents, including the arrest warrant and search warrant affidavits.

Merritt previously said that he didn't think Guyger went to Jean's apartment accidentally but that he didn't have a theory of what happened.

Jean was buried Monday in his home country of St. Lucia, where mourners gathered demanding justice for his death.