@Randall Patrick,
Let's say, for humor sake mind you, that there is a God. By all religious definition yes, he could kill himself. However due to the laws of nature, which even those I don't fully believe in, we can say that he cannot kill himself because he isn't "here". God is said to be able to be in two places at once, because he can do anything, so is it outside the realm of thought to believe he can be dead and alive at the same time? I don't think so.