The National Rifle Association, the most powerful US pro-gun lobbying group, demanded Friday that armed police be deployed to every school in the country, saying it was the only way to prevent more violence like the mass shooting last week that left 26 victims dead. The NRA, whose reaction to the national tragedy had been much awaited, ceded no ground to those calling for tougher legislation on gun ownership, and blamed politicians, media and violence in mass culture for killings like the Newtown school massacre.Duration: 00:43