SWAT teams are like a military invasion and not appropriate as a means to keep the peace. Look at Columbine, there were no heroes to save the children. Instead, they marched around with shields in front of them, taking precious time
evading the shooters.
The term "Peace Officer" describes the patrolman who answers a call for service. SWAT teams were not formed to "Keep The Peace." They came into existence when crooks would hide in houses and shoot it out with officers. The teams were trained in cover and concealment, utilizing as much time as they need to bring a problem to a non lethal solution. Hostage negotiators are brought along when needed. As drug dealers became better armed with high power rifles and fully automatic weapons, it would be negligent to serve a warrant on high danger targets without SWAT. And even now, SWAT officers are killed on raids. If you have a fool proof idea on how to keep the casualties to zero, please post your thoughts.