COLUMBUS, Ohio (WCMH) – A mistrial was declared Friday after a Franklin County jury was unable to decide whether a former Columbus police vice officer should be found guilty of murder.

Judge David Young dismissed the jury after it reported for the third time that it was deadlocked. The case will be tried again.

The 12-person jury began deliberations Wednesday. On Thursday, it had informed Young that seven jurors found Mitchell’s use of force when he shot and killed Donna Castleberry reasonable, two found it unreasonable and three were undecided.

During the seven-day trial, Mitchell took the stand in his defense, testifying that he had feared for his life when he killed Castleberry, 23, in August 2018.

“We’re proud of the job that the prosecution did, trying this case. As a family, we’re disappointed in the outcome,” said Bobbi McCalla, Castleberry’s sister.

Friend Lauren Talbott added: “It’s devastating. It was really hard to see all those things and hear all those things for the first time. And it will definitely be hard to do it all over again, but we’re not giving up. It’s not over.”

Mitchell’s attorney told NBC4’s Jamie Ostroff the former officer’s family was frustrated but respectful of the outcome.

Franklin County Prosecutor Gary Tyack’s office made a statement Friday afternoon thanking “each juror for their hard work and dedication to their task of considering this case.”

Tyack’s office added: “The State of Ohio will be carefully reviewing all available options to bring finality to this matter and will make a public announcement in several days.”

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The prosecution argued Mitchell used excessive, unreasonable force against Castleberry, while the defense argued Castleberry presented a threat that warranted Mitchell’s use of force.

If found guilty, he could face anywhere from three years to life in prison.

Mitchell remains under federal custody pending an unrelated case in which he is accused of forcing women to have sex with him to avoid arrest. The federal case against Mitchell as well as the vice unit’s handling of the arrest of an adult performer in July 2018 played a role in the abolition of the Columbus vice unit in March 2019.