But if SWAT is on the case then they can surround the place before they knock. And they can get a damned plumber if they think there's evidence worth getting down a drain or toilet.
None of that justifies no-knock raids which endanger lives.
Some might say that the element of surprise might save a life of someone inside who might be in danger from a perp, however I can't see that this will happen very often if at all. If the perp knows he's surrounded by SWAT why would he commit another crime by killing, harming, or taking another occupant hostage when he knows he's had?
In our surveillance society, even if the target got away, he wouldn’t get very far. It’s not like someone can go West or cross the border and start a new life.
These no knock raids put everyone at risk, Now it looks like we’ll also face very inconsistent and unconstitutional laws, 1st and 2nd amendment, a lot of people just won’t comply and anything can happen.