Peter Bergen : The Washington Navy Yard shootings not an isolated case . Comment: Bergen says it 's good that Defense Department is reviewing flaws in security . Bergen : Abdo had applied for a conscientious objector status discharge because of his Muslim faith and cited Hasan 's 2009 attack as an influence on his own murderous plot . One issue that slipped through the cracks was status of contractors .
Peter Bergen : The Washington Navy Yard shootings not an isolated case . Comment: Bergen says it 's good that Defense Department is reviewing flaws in security . Bergen : One issue that slipped through the cracks was status of contractors .