Mr. Diaz said semiautomatic weapons, including the AR-15, are increasingly being used in the killings of police officers, whose vests often provide little protection against such firearms.
An AR15 in .223 does easily penetrate the soft body armor that police wear. However, so does about every other center fire rifle round! So when the MSM cites crap like this, read between the lines--they are either ignorant and don't do even the most basic of research (unlikely), or they really want to set the precedent for banning ALL rifles, and eventually all guns (how many pistols kill cops after all?). That is the goal of the Brady campaign, to eliminate guns, and they put out all kinds of false or one sided info, and the MSM eats it up because they have the SAME agenda. Heck, they use the term "assault weapon" specifically to make it sound scary, and trick idiots into thinking they are automatic, not at all because of ignorance.
Steel tipped M855 ammo can also pierce steal plates, but I've never heard of it being used in the murder of someone wearing bodyarmor. Not a single one.