DENVER (KDVR) — The family of a woman killed while walking her dog near Coors Field almost a year ago and a survivor in the shooting have filed a lawsuit against her accused murderer and the former police officer who owned the gun used in the shooting.

The suit was filed on what would have been on Isabella Thallas’ 22nd birthday. She was the young woman shot and killed on June 10, 2020, outside of an apartment complex near Coors Field. Her boyfriend Darion Simon also suffered two gunshot wounds but survived.

An attorney for her father, Joshua Thallas, and an attorney for Simon, filed the lawsuit against Michael Close, who is charged in the shooting and has pleaded not guilty by reason of insanity.

The lawsuit was also filed against former Denver Police Department Sgt. Dan Politica and his company Tyrant Arms, LLC. FOX31 has previously reported the gun used in the shooting belonged to a Denver officer.

The Denver Police Department released a statement in January that said: “Close, a friend of a Denver Police officer, took the rifle from the officer’s home without the officer’s knowledge or permission. Upon learning his rifle was missing and that it may have been used in this homicide, the officer notified investigators that the rifle belonged to him. The rifle was not issued to the officer by the Denver Police Department.”

Politica resigned from the department in February.

According to Craig Silverman, the attorney for Simon, they question if the gun was stolen — a question he claims they have asked the Denver District Attorney’s office without a direct answer. Silverman said he hopes the lawsuit helps in getting the Simon and Thallas family some answers.

FOX31 reached out to the DA’s office for reaction to the lawsuit and the attorney’s claims that office has not offered sufficient information about the weapon used in this case. We have not heard back.