So what happens when it is a gang of thugs that decide to holler "Police Search Warrant" as they bust in your door?Bingo.
Even in the SWAT raids against known violent criminals that I've seen on TV, they always start yelling "Police, search warrant" before they hit the door, even if it's only a few seconds before. There is no way anyone inside could not know it was the police...and if there were any question, what kind of moron starts shooting at an unidentified target. Sounds like the instances you hear about when some idiot shoots his own son or daughter because they came home unexpectedly.
If it isn't the police and you shoot, it might save your life. If it is the police and you shoot, you are almost certainly dead.
One thing I noticed in the video of the District Attorney at the 0:35 mark is that he made reference to the fact that the shooter was known to police and infers that such knowledge played a part in obtaining the warrant.
No knock warrants should be banned or severely curtailed.