A few years ago, a pedophile suspect quickly shot and wounded two pursuing Kitsap County deputies in a Walmart parking lot in Port Orchard, WA, using this exact method - running away and shooting behind him. I tried it out using a Glock 19 airsoft pistol and I was surprised at how many rounds I was able to put on target. The gun moved so much that I couldn't use the sights so I just used the sihouette of the pistol as my "sight".
The pedophile suspect was engaged and shot by another deputy, which shattered his femur and he collapsed to the pavement. His underage girlfriend, that ran away from home in Utah to be with him, ran up to him as he lay on the pavement. He shot her once in the chest, killing her then he turned the gun on himself.
The entire incident was recorded by Walmart security cameras and released by Washington State Patrol.