How to make sure peace officers aren't trusted....

First of all, you get a narcotics warrant and perform a no-knock raid on a man with no criminal record, apparently without adequately announcing yourself--and of course without any recording devices to show what actually happened.  We can afford millions for SWAT training, but not $400 for a simple video camera, of course. 

When the victim, thinking he is the victim of a home invasion, is holding a gun, make sure your SWAT team has their guns on full auto--nothing says "respect for citizens" like spray and pray in their own home, endangering not only the guy with a gun, but also anyone else in the house.  (full auto inferred from 71 rounds in 7 seconds...and the fact that the guy lived for about an hour after the attack without medical attention....obviously the bullets came fast, and they weren't hitting well, either)

Then, despite the fact that you've secured the house in the first 30 seconds of the operation, prevent paramedics from administering aid for over an hour, resulting in the victim's death, and then proceed to lie on the official report, claiming that he managed to fire his weapon when he didn't.  Bonus points if you, as did the Pima County SWAT team, claim nonexistent damage to your shields from the shots he didn't fire. 

(of course, lying on an affidavit like this is called "perjury" for the rest of us)

Finally, make sure that you don't find any evidence of the alleged crime being committed, but proceed to say you found evidence of a "conspiracy" to commit an unnamed crime.

For this, the Pima County SWAT team wins "Jackbooted Thugs of the Week," I think, and hopefully some of them will get to pursue new career opportunities in the graybar hotel making license plates.  Pray for the consolation of his widow and child.