Shelby shot and killed Crutcher, 40, on September 16, 2016, after encountering him outside his SUV which was stopped in the middle of a Tulsa street.

Tulsa County prosecutors charged Shelby with first-degree manslaughter and a jury acquitted Shelby on May 17, 2017.  

Shelby didn't want to speak on camera about the announcement, but her attorney did. Attorney Scott Wood said they didn't even know about the investigation but are relieved about the outcome.

Related Story: Not Guilty: Jury Acquits Betty Shelby In Terence Crutcher Shooting 

"It is good for reconfirmation of what we've said all along," Wood said.

"They would have had access to all the videos, and I did understand that they had a copy of the jury trial transcript, so I am certain it was a very, very thorough investigation."

In a news release, the Department of Justice said a team of some of its most experienced civil rights prosecutors and FBI agents conducted a comprehensive, independent review of the events surrounding the shooting. The release says federal authorities examined all of the material and evidence in the State case generated by the TPD, the Oklahoma State Bureau of Investigation and the Tulsa District Attorney’s Office.

The Department says it also reviewed additional evidence presented during the trial and the trial transcripts. The FBI also enhanced video footage of the shooting in an effort to increase the Department’s ability to analyze the circumstances of the shooting.

Federal investigators determined there is insufficient evidence to prove beyond a reasonable doubt a violation of federal law. The DOJ says the evidence is insufficient to establish beyond a reasonable doubt that Officer Shelby’s use of force was “objectively unreasonable” under the Supreme Court’s definition. The DOJ also says the evidence is not sufficient to rebut her assertion that she fired in self-defense with the mistaken belief that Mr. Crutcher reached into his vehicle in order to retrieve a weapon.

It says the evidence is also insufficient to establish that Officer Shelby acted with the specific intent to break the law.

"She acted reasonably, and she acted just how she was trained to react in a situation like this," said Attorney Scott Wood.

Wood said Shelby is moving forward with her life, working as a deputy with the Rogers County Sheriff's Office, but some days are harder than others.

"It's always difficult when you have a lawsuit still pending - and can be pending for several years - to kind of put anything behind you, so you know it's an ongoing process for her."

The DOJ says the investigation into this incident has been closed, but it says the decision is limited strictly to the Department’s inability to meet the high legal standard required to prosecute the case under the federal civil rights statute; it does not reflect an assessment of any other aspect of the shooting.

Wood says the DOJ's decision won't have any impact on the civil case the Crutcher family filed against several local entities. That case is still working its way through the legal system.