I'm making no assumptions, I'm just saying what narrative the evidence supports.
Also, here is a summary of the LAPDs policy on lethal force. I'm guessing that the po po in Missouri probably have a similar one:
LAPD officers’ use of force is concise, consistent with prevailing law, and based on best police practices. Officers are permitted to use force that is objectively reasonable to defend themselves or others, to effect an arrest or detention, and/or to prevent escape or overcome resistance,” Izen said. “Officers are taught to evaluate a suspect’s behavior, the severity of the crime a suspect is committing or about to commit, and whether it is reasonable to conclude that the suspect’s behavior might cause serious injury to an officer or another person.
“If a suspect’s behavior is likely to cause serious bodily injury or death, an officer can, by law and under LAPD policy, use deadly force,” Izen added. “In using deadly force, officers can fire their weapons only to stop deadly threats to keep themselves and the public safe, and can continue to fire until the threat has ended.”