Maybe “people” should have shielding and housing murders training.
You are assuming that the people who lived in the house know the perp and the crime he may have committed.
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures
The guy they were looking for was a murder "suspect" as in still innocent.
A stun grenade, dynamic entry IMHO falls under unreasonable searches
There are many other ways to achieve the same outcome without the SWAT team pretending they are raiding an AL Queda hideout