I think they should go further than this and install metal detectors to net those who conceal carry. But trust some people to beat the system to beat the devices in these days of runaway technology. In this era of mass shootings and terrorism, it would be suicidal to allow individuals to conceal carry. I suppose someone open carrying is not likely to have a delinquent predisposition as the confidence he will derive from open carrying without arousing suspicion would yield a positive emotional dividend.
Virginia Tech shootings and others just proves that the issue of gun ownership has good horribly wrong by creating lopsided situations against those who don't fancy them. This is a form of brinkmanship by extension to argue that gun free zones are targeted by dint of being sitting ducks in the face of a deranged assault by am individual from a zone that allows gun ownership. It follows that the only water tight solution is to create a trainee police reserve unit to live within the populace and then ban gun ownership as we know it today. It would then be easier to crack down on gangs and the black market. It doesn't help matters that those who commit shootings are licensed gun owners as illustrated in Virginia Tech university. There is no way to profile a typical offender.