Fixed it for you.

“During the execution of this (federal search) warrant, one of the officer’s weapons discharged officers discharged his weapon,” reads a statement issued by Attorney General Joseph Foster.

Contrary to what Attorney General Joseph Foster might wish, those things don't discharge themselves. It takes a finger on the trigger. The officer either intentionally shot the grandmother when he saw her move or he had his finger on the trigger and pulled it when her movement startled him. Just saying...

H/T to Firehand.