What you have here is a tragic situation occurring. As you stated: The Pima County SWAT officers approached the Guerena residence and announced the service of a search warrant and sounded a siren. Unfortunately his wife not he heard that announcement or the siren. The SWAT team breached the residence, unaware that the residents didn't not hear the warnings they supplied, and saw a man pointing a weapon at them. They saw that weapon pointed at them, and responded with deadly force. Remember they are there searching for drugs, and in most cases like these there are bad people willing to fight it out with police. They do not know what becomes known until after the fact.
For you to suggest that this tragic incident is solely the fault of the SWAT team, is ludicrous.
You said “warrant of any kind”.