thank you for not break my fingers. [ laughter ] >> i later showed this video to brendan heroine, a professorth and human security. >> anything that we can use in order to buy time for our children, is a good thing. but hopefully, every teacher that is given a white board has some level of training. you can't just do it one time and say okay i got it. it's too late to read the instructions once the shooting starts. >> but what about the role of bulletproof batches in schools? i wanted to hear from other mothers that the insert is a good idea. >> i think it's a false sense of security. even if i hold this, i think this is heavy. if you can flee from an assailant, i think this would weigh somebody down. >> jennifer cropper disagrees. >> put them in the backpack. okay, you have a bulletproof insert in your backpack. my child would say yes i can have the other kids get behind me. but in actuality they might be better off ditching their backpack and running. >> you're in different situations where you're not able to run and not able to go anyplace. i want him to know that there's something that he