I'm not sure if this has been covered before or not, so bear with me.
I have a friend who is willing to sell me his brand new LEO Colt AR15 in 9mm and a dozen mags for it at a ridiculously low price. I have been in the market for one, but I wanted it for personal use, so I can SBR it. Yes,I am a LEO and could use it for duty if I wanted to but I would rather have the 9mm for personal use because I already have a 5.56 cal duty rifle.
My question is, if I were to take all the evil features off and put it into a post-ban configuration, could I legally own this rifle for personal use, therefore allowing me to SBR it, even with the LEO marked lower??

Thanks in advance.....

Given the above conditions - yes that would be legal.

Here is the 'gotcha' it should be in a post-ban configuration before you take control of it - at the very least keep it broken down when you take possossesion of it.  Other wise you will unlawfully be in possession of a "post-ban semi-automatic assault weapon".

So, Forest, basically if he were to sell it to me in a post ban configuration-even though its marked LEO only, I'll be ok?? Can you forsee any problems with ATF when I apply to make it a SBR?

Yes you will be OK

The words 'For LEO use only' have ZERO legal meaning.  The law indicates its status as an AW is the presences of specific features not markings.

Heck there is even a letter on this posted in the Bushmaster forum (somebody wants to buy a LEO marked lower for kicks and grins).

You should not have a problem with the BATF at all when registering as a SBR.