Secret New York City police documents have revealed a confidential police informant spied on Reverend Al Sharpton’s National Action Network as the group was meeting to discuss protests against the police killing of Sean Bell. The informant attended a meeting held by the group in 2008 after three detectives were acquitted of killing of Bell, who died on the morning of his wedding in 2006 after police fired 50 shots. A police document shows the informant gave police a description of protest plans and the names of people involved.