10:43 a.m. update: Proceedings have ended for the day. The trial is expected to resume at 9:00 a.m. Monday.

COLUMBUS, Ohio (WCMH) — The first week of former Columbus Police vice officer Andrew Mitchell’s murder trial concluded Friday after the state rested its case and defense attorneys brought in two witnesses.

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, fired fatal shots against Castleberry after she slashed his hand with a knife.

While prosecuting attorneys claim Mitchell used excessive, unreasonable force against the 23-year-old, the vice officer’s defense attorneys contend that Castleberry presented a threat that warranted Mitchell’s use of force.

On Thursday, Joshua Durst, of the Ohio Bureau of Criminal Investigation, took the stand Thursday, where he was questioned about the trajectory of bullets fired from Mitchell’s gun that killed Castleberry.

Durst testified that there were no discrepancies between the physical evidence presented in the case and Mitchell’s prior testimonies with law enforcement.

He also claimed that he could not conduct gunshot reconstruction or blood spatter analysis of the car in which the shooting happened because Columbus police had already swept the car during their investigation.

After Durst left the stand, the prosecution called David Loomis, a senior forensic audio/video analyst for the Ohio Organized Crime and Investigations Commission, part of the Ohio Attorney General’s Office, to testify.

Loomis, tasked with analyzing the video that showed the interactions between Mitchell and Castleberry, said the audio and video quality was poor, occasionally making it difficult for him to clarify certain questions about the incident presented by prosecutors.

After Loomis, the protection called retired police detective and Critical Incident Review expert of police interactions, Jamie Borden to testify as an expert witness.

Borden testified about his work doing C.I.R. for different police departments, prosecutors’ offices and court cases.

While studying the shooting of Castleberry, Borden said the time that passed between each gunshot fired by Mitchell — also known as cadence — was at a minimum around 1.9 seconds, which he described as a “much slower and deliberative process” than the average use of force cadence of 1/4 of a second.

He said in the average use of force case, where officers are under “spontaneous and continuous attack,” they typically fire a weapon at that average 1/4 of a second rate, meaning about five rounds are fired in one second.

Borden said there was a “high potential” that Castleberry did not believe Mitchell was a police officer at the time of the shooting, as there were no identifiable markings indicating that Mitchell was a member of CPD.

“Was the officer identifiable as a police officer? Because that’s going to effect what’s going on,” Borden said. “(Castleberry) believed that they were going to be harmed – believed that they needed the police, and all of that is evidence in the audio evidence.”

Despite Castleberry’s initial disbelief that Mitchell was a police officer, Mitchell reportedly handcuffed her — a tactic that Borden described as poor. He said that officers are typically disciplined for being “hands on” with a person without a backup because of the potential for danger.

Borden testified that Castleberry was likely trying to defend herself from Mitchell and thus slashed his hand with a knife. He said her use of a knife was not a stab but more like a “slice across the hand.”

“It’s not an offensive move,” Borden said. “It’s defensive.”

In an exchange with Borden, prosecuting attorney Sheryl Pritchard asked:

“Once Donna cuts Mitchell, does that give him carte blanche freedom to kill her?” she asked.

“The answer is no,” Borden responded.

After Castleberry slashed Mitchell with a knife, Borden said no further attacks against Mitchell occurred. Given the “very long stretch of time” between the initial knife slash and the gunshots that killed Castleberry, Borden testified that the evidence does not support that Castleberry launched a “spontaneous, continuous attack” against Mitchell.

He testified that the use of force against Castleberry was not reasonable.

Once the state finished questioning Borden, defense attorney Mark Collins pointed to the expert witness’ lack of what’s called a LEVA certification obtained by forensic video analysts — likely to question Borden’s credibility in analyzing the audio and video of Castleberry’s death.

Collins also questioned Borden about past court decisions pertaining to law enforcement use of force, including Graham v. Ohio, which Collins and Borden both agreed determined that an officer is not supposed to consider the perspective of the other person, in this case Castleberry, when assessing a threat.

And, under Graham, Borden testified that Mitchell — who Collins said was left with 34 stitches and a blood transfusion from his hand injury — had every single right to use physical force to handcuff Castleberry.

Collins also scrutinized Borden’s claim that Castleberry did not know Mitchell was a police officer. According to Collins, a warrant was filed for Castleberry’s arrest days prior to her death — which Collins said she was aware of. Borden, who reviewed the case, said he did not know whether a warrant had been filed.

Although Borden testified that Castleberry perceived Mitchell to be a threat, he also testified that Mitchell perceived Castleberry to be resisting arrest and noncompliant.

Wednesday, Columbus Division of Police officer Matthew McDaniel, CPD detectives Lara Evans and Greg Sheppard testified. 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.

Castleberry was shot and killed by Mitchell during what was originally described as an undercover prostitution operation. Police said Mitchell was attempting to take Castleberry into custody inside of an unmarked vehicle in the area of Bellows Avenue and South Yale Avenue.

According to police, Castleberry stabbed Mitchell in the hand in the moments leading up to the shooting. Court documents state Castleberry thought the attack was an attempted kidnapping and rape since Mitchell did not present a badge and was wearing plain clothes at the time.

Mitchell claims the shooting of Castleberry was in self-defense.

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 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.