How do they know the shooter killed himself, when initially they said he only had handguns

Now that they know the kids were killed with a rifle, have they said the shooter also used a rifle to kill himself? Was it the same one? Who did the ballistics? Initially we were told he only used handguns, and going on that info, we presumed he used a handgun on himself.
Are they just making this shit up every time they get caught in another lie?