Dynamic entries depend on “surprise, shock, and speed” and you go to
the suspects. With deliberate entries like “surround and callout” the
suspects come to you. Knock and announce requirements vary for each
jurisdiction and must be followed.
Remember Murphy's Law. Unexpected obstacles, dogs, darkness, etc., can throw off even the best-laid plans. Effective perimeters don't happen by accident. They require tactics, planning, and precision coordination.
Knowing the route is critical. Some years ago I participated in a major raid where the lead vehicle had trouble finding the target because they’d never seen it, and darkness obscured the address.
Preparation for searches and raids starts long before SWAT is ever
requested. It begins with deciding which warrants service SWAT will do.
Some teams handle all of their agency’s raids, while others only handle
the highest risk. My guess is that the majority of SWAT teams fall
somewhere in between.
It could be said that a raid is a raid and a search is a search.
However, that would be entirely wrong. The raid and search techniques
and tactics of patrol officers differ from those of detectives. And the
techniques and tactics of SWAT raids and searches are substantially
different from those of both patrol officers and detectives.