Officers Mike Ringgenberg and Dustin Schwarze were trying to arrest Clark early Sunday morning when he was shot in the head, officials said.
"While he was being legally detained, (Clark) chose to resist, fight officers, and seize control of an officer's handgun," Frederic Bruno, attorney for Schwarze, and Robert Kroll, president of the police union, wrote in a media statement.
At a news conference Kroll said Clark had control of an officer's gun belt and pistol.
"It was in the holster and he had physical control of the hand grip," Kroll told reporters.
Protesters have said witness said Clark was in handcuffs when he was shot.
Bruno and Kroll disputed that.
State and federal investigators are looking into the shooting. Officers and paramedics were responding to a call of a woman being assaulted. Authorities have said Clark was interfering with the woman's medical care when Ringgenberg and Schwarze tried to arrest him.
Kroll said Clark was trying to pull the woman out of the ambulance.
Parts of the incident were recorded on several cameras, but no video shows the entire incident, Drew Evans, the superintendent of Minnesota Department of Public Safety's Bureau of Criminal Apprehension, said this week. None of the videos will be released until the investigation is over.
That has angered protesters who have gathered outside a Minneapolis police precinct for five days.
Two men were arrested Thursday night after profanities were found spray painted on the precinct building, the police department's Twitter account said.
Earlier in the day, several politicians met with protesters outside the 4th district headquarters, including Keith Ellison, who represents part of Minneapolis in Washington.
"We must all be committed to establish the facts of what happened in the interest of justice," he said on Facebook. "We must come together to heal our community and work together toward justice and fairness. I call on demonstrators to remain peaceful, and on law enforcement to exercise restraint."
Overall, demonstrations on Thursday appeared to be less stressful than a day prior, when police used chemical irritants against some protesters and shot a marking round with green paint at someone they said had thrown two bricks.