Dallas Police and the Medical Examiner have a bit of a mystery on their hands this morning.  Just before 3 a.m, police received calls about shots being fired in South Oak Cliff. When they arrived at the neighborhood though, they found a pick-up which had crashed into a tree on Beckleycrest near South Polk. When they checked out the truck, the driver was already dead.  Now, the question is: did he die from hitting the tree or from some other cause?