Philadelphia is critical to next week's presidential election. This week hundreds of protesters have been marching through the city demanding racial justice after police killed Walter Wallace, a black man suffering a mental health crisis. Police shot him because he wouldn't drop a knife. A police spokeswoman said that Wallace advanced towards them and they fired fourteen shots, hitting Mr Wallace in the shoulder and chest. She added, ‘One of the officers drove him to a hospital, where he was pronounced dead’. This statement is contradicted by bystanders and Mr Wallace's family lawyer, who said that the family called for an ambulance because of his bipolar disorder. Mr Wallace’s father said, ‘Why didn't they use a taser?’ The marches began peacefully but became more confrontational as the evening drew on. Protesters are looting and ransacking businesses. The National Guard has been deployed with officers in riot gear.