BURY, ENGLAND  - MAY 24:  Rebecca Rigby, the wife  of murdered soldier Lee Rigby, grieves during a family press conference at the Regimental HQ of his unit, the Royal Regiment of Fusiliers on May 24, 2013 in Bury, Greater Manchester, England. Drummer Rigby was murdered by suspected Islamists near to his regiment's Woolwich Army Barracks. The UK's security services are facing a Commons inquiry after confirmation that the two men - who were shot and arrested at the scene and remain in police custody - were known to MI5. (Photo by Dave Thompson - WPA Pool/Getty Images)