michigan, thank you. so according to a cnn tally, the shooting at oxford high school was the deadliest at a k-12 campus in the u.s. since 2018 and the 32nd school shooting just since august 1st. for some, the short and long-term psychological impact for those involved including survivors, first responders and the people left grieving for the people that they lost, all of that is overwhelming. let's talk to peter langman, the author of "why kids kill: inside the mind of school shooters." peter, thank you so much for being with us. mark laid out a lot of the evidence that they had goings into what happened on tuesday. i'm interested in the fact that you're also a researcher with the national threat assessment center of the u.s. secret service. we can't always foresee a attack. it seems like they could based on the information we know. what is your gut reaction to