TULSA, Okla. >> Attorneys for a white Oklahoma police officer who killed an unarmed black man are asking in court records for investigators to keep as evidence a handgun that an anonymous tipster claims the man fired a day before the fatal shooting.

Tulsa police officer Betty Jo Shelby is charged with first-degree manslaughter in the Sept. 16 shooting of 40-year-old Terence Crutcher. Shelby shot Crutcher after she arrived on a street to find Crutcher’s SUV stopped in the middle of the road. Shelby has pleaded not guilty and is on unpaid leave.

One of Shelby’s lawyers, Shannon McMurray, said Tuesday that a man called last week and claimed Crutcher was seen Sept. 15 walking on a different street and firing a gun, and that police were notified and recovered a gun left in the road.

“What, if any, material value (the gun) has is to be determined at a later date,” McMurray said. “We don’t know, but both sides look at every piece of potential evidence to include and exclude. Otherwise, we wouldn’t be doing our jobs.”

Police found the gun more than 2 miles from where Crutcher was shot the next day. It’s not clear whether anyone was harmed in the alleged gun-firing incident.

Police spokeswoman Jeanne MacKenzie declined comment Tuesday. Police Chief Chuck Jordan has said that Crutcher did not have a gun on his body or in his SUV when he was shot.

Damario Solomon-Simmons, an attorney for Crutcher’s family, said Shelby’s defense team is trying to divert attention from the fact that Crutcher is seen without a weapon and with his hands up on videos from a dashboard patrol car and a police helicopter.

“It is sad, but not surprising, that Officer Shelby’s counsel continues to promote irrelevant information in an attempt to distract from undisputed facts that Officer Shelby shot and killed Terence Crutcher without provocation or justification,” he said in a statement Tuesday.