The Kilyn Lewis family filed a federal civil rights lawsuit against the City of Aurora, claiming the city’s policies, practices and “longstanding customs” led to his fatal shooting.

Lewis, 37, was shot by Aurora Police Department SWAT Ofc. Michael Dieck on May 23, 2024, while officers were attempting to arrest him on an attempted murder warrant out of Denver. Lewis was not armed.

Dieck’s use of deadly force was deemed justified by a Critical Incident Response Team, the 18th Judicial District Attorney, and an APD internal affairs investigation. 

On Thursday, the Estate of Kilyn Lewis, through Pikes Peak Probate Services, Inc., filed a lawsuit against the City of Aurora in the United States District Court for the District of Colorado, claiming that Dieck’s actions violated Lewis’s Fourth Amendment rights.

“Officer Dieck’s use of deadly force was unnecessary, unreasonable, excessive, and contrary to the Fourth Amendment,” according to the lawsuit.

It also claims that the city’s longstanding practices — including allegations of permitting APD officers to escalate encounters and use deadly force and failing to require adequate investigations and discipline — caused Dieck to use deadly force when it was unnecessary.

Aurora funds, operates and manages the APD, so the city is legally responsible for its officers’ actions, the lawsuit said.

It also points to the consent decree the APD entered into with the Colorado Attorney General’s Office in 2021, which went into place after an investigative team found patterns and practices of racially biased policing, excessive uses of force, and failure to record legally required information.

The lawsuit states the following about the shooting:

“The Lewis shooting is precisely the kind of predictable constitutional injury that adequate policies, training, supervision, discipline, and force-review systems are supposed to prevent: a planned apprehension of an unarmed person, conducted by specialized officers, transformed within seconds into a fatal shooting because officers rushed the contact, issued conflicting commands, failed to de-escalate, failed to use available time and cover, failed to use available less-lethal options, and treated a non-threatening movement toward compliance as justification for deadly force.”

Given the amount of time officers surveilled Lewis and the variety of resources the APD had to detain him, the responding officers should have been able to slow the contact, contain the area, use cover, communicate clearly and use less-lethal options, the lawsuit claims.

The city is simultaneously facing a state lawsuit from the Lewis family alleging wrongful death. Six of the seven claims have been dismissed by the plaintiff or the court, according to City Attorney Pete Schulte. The only remaining claim is an allegation of excessive force.

A City of Aurora spokesperson told The Denver Gazette that the city has not been served with a new lawsuit and cannot comment on pending litigation.

“Unlike the Plaintiff’s attorneys in this case, I will not make statements about the case that have the potential to wrongly influence the jury pool,” City Attorney Pete Schulte told The Denver Gazette Tuesday. “The true facts will come out in a courtroom in the trial of this case.”

Attorney Lisi Owen told Denver Gazette news partner 9News that police departments have an “obligation to make sure that their officers are competent.”

“This lawsuit is not the first lawsuit to allege a systemic problem with killing, in particular, unarmed black people in Aurora,” Owen told 9News. “If officers know that they can kill people with impunity, they’re not going to be motivated to stop doing it.”