If he was such a big danger so all of 50 (!) SWAT members were sent to arrest him demolishing half of his parents' house on the way although there are no reported resistance, during that event, then why a week earlier he was let to travel by car 3 days accross the country, potentially compromising lives, health and safety of the members of general public?
Why he was not arrested whilst being in Pullman? He was a POI before started the trip, as FBI was already tailing him; he was allegedly identified as dangerous (hence the overpowering arrest).
This does not go both ways.
He was either a dangerous criminal so excessive power was indeed needed to overcome him, or or he was not.
This has to be addressed and I will not be suprised if his defence team logs a complaint/claim whatever the law recommends in such cases.
I’m certain they will have chosen to arrest him as soon as they had what they believe to be sufficient evidence to convict. They can’t go around arresting every person of interest without evidence to support doing it, and they also have to be careful to avoid putting themselves, members of the public or the suspect in danger as much as is reasonably possible. They arrested him when they could in the safest way they could arrest someone they suspect has murdered four innocent people.