Because children, young adults and teachers in our schools continually get massacred in places that should be safe havens of learning by mentally ill people who legally obtain guns.

When a judge deemed Virginia Tech shooter Seung-Hui Cho a danger to himself due to mental illness in 2005, that ruling should have disqualified him from buying a handgun under federal law.

It didn't.

His slaughter of 32 people on April 16, 2007 raised questions about the efficacy of instant background checks for firearms purchases by the mentally ill, and yet the loophole still exists. Under federal law, anyone who has been judged to be a danger to himself or others because of mental illness, as Cho was, should be prohibited from buying a gun.