Since May of 2007 9 police officers have been killed by CCW permit holders. Of the 200+ people killed by CCW permit holders the majority involve criminal convictions against the shooters. Not to mention a number of high profile murders committed by CCW permit holders. The worst case is not someone uninvolved gets "hurt."
At the core of your argument is that only highly trained police officers can use firearms effectively. The sad statistics you give disprove that, and prove my point that the ability to kill is inherent in the human state and requires little training (which should be obvious to anyone who's studied either history or the Bible). But do they prove that citizen CCW or gun ownership is bad?
Not at all. The fact that the civilian had a license to legally carry a firearm had nothing to do with his illegal actions. i.e. the piece of paper in his wallet didn't matter, he would have had a gun and did what he did anyway. People don't become magically better or worse when they get a license to carry a firearm, or even a badge.
So those murders would have happened anyway. Such as the case in PA where one white supremist shot 3 police officers with an AK47 -- not a concealable weapon, not a weapon you can legally conceal with a CCW -- but 1/3rd of the statistic you state.
People who are going to kill, be their targets cops or otherwise, could care less about facing a potential concealed weapons charge. While some people have murdered with CCW's, overall the murder rate has gone down since legal CCW has spread like wildfire. Probably not because of the CCW, but simply because CCW does one thing and only one thing:
It empowers law abiding citizens (you?) to carry weapons. For non law abiding citizens ... they never waited for a license. And even if they obtain one, it does nothing to make them more murderous.
There are somewhere around 4 million licensed civilians with CCW's in the U.S. The vast, vast majority of them law abiding and yes ... many have saved lives with their licensed weapons. Including the lives of police officers.
Here is a link that gives some details. *kc3.com/self_defense/ officers_peril.htm*. There are quite a few more polices officers helped there than the 9 you list that were murdered. Except in these cases it was the CCW the law abiding civilian had that helped them out, because the law abiding citizen won't carry if it's not legal. The murderer will. Again ... virtually nothing but positive for legal CCW.
This doesn't touch upon the biblical or Christian reaction to carrying a lethal weapon for defense of self and others ... but clearly it's a good and responsible thing to do. If you live in one of the 40 states where it's absolutely allowed, and feel you are a candidate for the responsibility of carrying one and have no religious belief that forbids it ... I highly recommend you get your license, own a firearm, and learn how to use it. Not because you necessarily want to carry on a regular basis, but because it's a good thing to have.
And whether you believe we are post trib or pre trib, the Bible speaks of difficult times to come and it's clear Christians aren't exempt from them. Don't limit your tools unnecesarily.