Proceedings have ended for the day and are expected to resume Tuesday at 9 a.m.

COLUMBUS, Ohio (WCMH) — The trial of a former Columbus Division of Police vice officer will enter its second week Monday at 9 a.m. as the defense continues to present its case.

Former officer Andrew Mitchell is charged with murder and voluntary manslaughter for the August 2018 shooting death of 23-year-old Donna Castleberry. Mitchell, while working as an undercover officer during an attempted prostitution sting, fatally shot Castleberry after she slashed his hand with a knife.

While prosecuting attorneys claim Mitchell used excessive, unreasonable force against Castleberry, the former officer’s defense attorneys contend that Castleberry presented a threat that warranted Mitchell’s use of force.

On Monday morning, Mitchell himself took the stand, where his defense attorney Mark Collins questioned him about standard procedures and training of the Columbus police VICE unit — including de-escalation techniques and appropriate scenarios in which officers should use force.

Mitchell testified that in cases where a suspect is noncompliant while an officer is attempting to handcuff them, he said officers are trained to use the least amount of force as possible to avoid injuring the suspect.

While Castleberry was allegedly choking Mitchell, kicked him with her feet and slashing him with a knife, Mitchell said he thought she was trying to kill him.

“I was fighting for my life – I couldn’t remember the (gunshot) sequence,” he said. “I still can’t remember a lot of the things if it weren’t for the video.”

Mitchell also claimed that Castleberry posed a real, actual threat towards him, and he had every right to put his hands on her and shoot her.

“I don’t wanna shoot anybody, but that’s the only thing I could think of to get out of that situation,” Mitchell said.

After Collins finished his line of questioning, prosecuting attorney Daniel Cable replayed the audio and video recording of the exchange between Castleberry and Mitchell.

Cable asked Mitchell why at one point in the video, shortly after he fired the first gunshots at Castleberry, he said “f—— nightmare.”

“I was saying f—— nightmare because I was cut, and I just shot somebody,” he said. “It was a nightmare.”

Kevin Davis, a law enforcement expert witness and former officer for the Akron Police Department, was called to the stand by defense attorney Mark Collins after Mitchell finished testifying.

Davis, who reviewed the evidence from Mitchell’s case, said the former Columbus police officer was “objectively reasonable” in using force against Castleberry.

He testified that after Castleberry repeatedly denied claims that Mitchell was a police officer, Mitchell went above and beyond in showing her his identification as law enforcement — a move that Davis said were Mitchell’s attempts to de-escalate the situation.

For the duration of the encounter between Castleberry and Mitchell, Davis testified that Castleberry, who he said had no lawful right to resist arrest, presented a deadly, continuous threat toward the vice officer.

“Once she cut him, especially on his gun hand, seriously diminished his ability to protect himself,” Davis said.

On Thursday, the prosecution also called retired police detective and Critical Incident Review expert of police interactions, Jamie Borden to testify as an expert witness. While studying the shooting of Castleberry, Borden testified the amount of time between each shot Mitchell fired, known as the cadence, showed a “much slower and deliberative process” than the average use of force, which Borden said is approximately .25 seconds.

Members of the Ohio Bureau of Criminal Investigation took the stand for the prosecution Thursday. CLICK HERE for a full recap.

Columbus Division of Police officer Matthew McDaniel, CPD detectives Lara Evans and Greg Sheppard testified Wednesday. The prosecution and defense went through group text messages between Evans, Mitchell, and other CPD officers among other items. CLICK HERE for a full recap.

Mitchell has been held in 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.

The former vice officer faces life in prison if convicted of the murder charge. If convicted of involuntary manslaughter, Mitchell could be sentenced to between three and 11 years in prison.