Help to shoot a bullet hit victim falling to ground in wide shot?

[heil_cf2]

in our zero budget movie, there is a scene where an actor get shot in the head inside a parking lot by another actor and fell backwards, we need to shoot it in one continuous shot from the bullet hit and him falling to the ground from a low angle from behind where we can see the parking lot floor too, camera will follow him from behind, but we can't find a solution how to do it, any ideas please??

 

[clang]

Why not just film him reacting and falling, then next shot get in close and show the blood etc. Given that it's a wide shot, any practical blood effects would barely be noticed by the audience anyway in the second or so of his fall, unless you were wanting an 'exploding head' cheesy effect.