kinematics - How to calculate a firing location from point of impact data?

I would like to know how to calculate the point at which a bullet is fired from a gun given information from the scene where the bullet falls. The scene would contain the point of impact (GPS location data), the angle at which the bullet decended (taken from the ceiling to the actual point of impact), and the height of the point of impact. As you can see, I am trying to determine weather a person who fires a bullet into the air and it impacts someone, can be located via some physics and mathematical formulas. From the crime scene we would also have the specific bullet type and its dimensions and manufacturers ballistics trajectory information. I've checked some sites for ballistics and there are many tables calculating the ranges of specific bullets and guns. I hope to use this data somehow. If someone has already done this, please let me know.