Yeah, I remember that story, he killed his mom because they hid the Xbox (or halo 3) for a whole year and when he knew that his parents did that he decided to kill them.
He approached his parents and told them to close their eyes because he was going to give them a present, when they did that he pulled a pistol from the back of his pants and shot them point blank in the head, his mom fell dead right away then he putted the pistol in his father hand to make it as if the father did it and commit suicide but somehow the father survived the ordeal and told the police everything.
The bottom line is that the kid was a crazy teen, games didn't kill his mom, he did it.