A shooting at a Walmart in Mississippi has left two people dead and a police officer injured.br Officials say the male suspect, whose name has not been released, was a former employee of the store who had a personal grievance with a manager.br The suspect was shot two times during a stand-off with the injured officer, who was shot once.br Both are being treated at local hospitals.br Police said their recent active shooter training prevented more deaths.br Walmart issued a statement offering condolences to the victims and their families.