Some posters seem to be surprised that today's felons might come to the party equipped with body armor.
Consider this: Our nation has been in a shooting conflict for almost a decade. At the start of that conflict, very few military personnel routinely trained with or were even issued modern body armor. Prior to 2001, some military folks were issued flak vests, but those mostly spent time in wall lockers or sea bags.
As the current war developed (and casualties increased), armor became ever more widely spread and eventually mandated...for everyone.
There will soon be nearly 2 million veterans who were routinely issued body armor sometime in the last decade. About 2.9 million more continue to serve in the Armed Forces today. Perhaps 150,000 - 200,000 new veterans leave the services each year (just a guess).
That means that 4+ million adult veteran Americans who understand the concept of personal body armor are spreading that experience across the general population. Add in almost universal use by American law enforcement and daily depictions of armor in the mass media culture (computer games, television, films, etc.)...there are a hell of a lot of Americans with a clue about personal ballistic protection.
In the 1970s, most people (including police) didn't even know what armor was. Today it's different.
BTW: I'd not trust Level II to stop .30 Carbine FMJ until the round got out a ways...say 150-200 yards. Maybe not then either.
