tonight on cnn, don, talking about how students were trying to arm themselves with scissors and calculators. >> alex, we're going to go now to the sheriff in oakland. this is the undersheriff, michael mccabe. let's listen in. >> you guys all set? >> just a reminder again, if you have any phones or anything, please silence them, because this is streaming, and it picks up every little bit of noise, so appreciate that. obviously we're here for the worst kind of tragedy we've seen