Are you kidding? Another sad incident and we can be so grateful it did not end in death. But how many does that make? How about: https://en.wikipedia.org/wiki/List_of_school_shootings_in_the_United_States Look at the most recent. That's 15 dead in three months. A pattern that has emerged in some of these killings is that the perp was male, white and was angry that 1) he hadn't got a girlfriend, 2) No girl liked him and 3) He hadn't gotten his end away. Now that's a pattern. What I do agree with is that it may be indicative of a possible trend with knifes being carried by certain (very few) individuals. But to call 4 incidents over many years, a pattern is stretching a point too much. That schools need to have a heightened awareness of a possible increase in knife carrying is obvious but does this mean we flood schools with metal detectors because it's a pattern?