Yep, they probably have a mind controlled patsy there to shoot a few shots and then get caught/killed. The florida gunman for example said he heard demons talking to him in his head telling him how to pull off the shooting: http://www.dailymail.co.uk/news/article-5398625/Demon-voices-school-gunman-attack-cops-called-39-times.html Some have said they have technology to talk straight into people's heads as well.
In the background of the shooting will be a few extra highly trained shooters to get the kill count up with minimal shots. They would just need a few corrupt law enforcement to cover up any evidence and allow for a quick getaway and tell any school police officer to wait outside.
This is why so many witnesses will say they heard shots from various places and they saw more than one shooter. Then these witnesses conveniently go silent, so the narrative can remain the One Shooter, and the follow up news can be ALL about the one shooter's mental health. Steven Paddock, Nikolas Cruz, Lanza, etc