If a system like this were to be implemented, I find that it should be separate from traditional score, so Terrorists wouldn't just be battling Police at main armor all the time to get more score. I think it would be better if Terrorists were to only get those kind of points from killing the president, the police from killing terrorists, the presi from surviving and Security from being near the presi (the range of which ought to be bigger if the pres is in a vehicle). Civilians ought to be excluded from this system.
Atleast, that's my two cents.