Here is another piece to the 'Who killed TUPAC' puzzle. As members of the Hip Hop community, it's up to us to get down to the bottom of this murder. We can't accept "cold cases" in the death of our influential young poets because that would solidify the status quo, that killing one of 'us' is no big deal. And 2Pac's former bodyguard, "Big Frank", the one who was suppose to be guarding Pac the night of his death, may have taken some secrets to…