Until we as a society learn how to identify those individuals with mental illness - and how to help them, as well as come up with some sort of legislation that will tighten controls of who is allowed to have guns, this type of incident will continue to happen.

We need to come up with a better application process for those individuals who want to purchase a gun - including some sort of section regarding the mental state of the applicant.

We need to remove the stigma that accompanies mental illness.

And yes, SagaciousDom Sir, these sorts of incidents will continue to occur until we as a society stop it. How, I don't know...