No I asked the right question and you're dodging it.
You may need to research
rules of engagement for police officers.
When possible, making contact should be accomplished prior to the armed individual(s) becoming active shooters. The goal is to proactively minimize injury and death to innocents by positioning ballistically protected officers in close proximity with the threat,
so that accurate application of deadly force can be expeditiously applied, if necessary.
Immediate Action Rapid Deployment tactics should only be established by law enforcement agencies willing to establish clear policy, provide initial and recurrent training in IARD, and provide all first-responding officers with high quality ballistic shields that allow each officer the ability to deliver accurate handgun and/or long-gun firepower when safely positioned behind a lightweight ballistic barrier.
Patrol officers must be capable of neutralizing the threat before any further aggressive action can be taken against innocents, including the officers. Quickly making contact is the key to a successful outcome, which is realistically determined by how many innocents are saved, and not by how many are initially murdered and injured prior to the arrival of the first responders. Delaying physical police contact until the armed suicidal individual(s) becomes "active", will lead to a higher casualty count.
The police had to assume the suspect was armed and act accordingly.