Police forces are one of the government agencies that routinely rely on PR campaigns for public assistance with investigations but also often seek to spin the news when criticism of police operations is anticipated.
The killing of Jean Charles Menezes
Following the revelation that British police gave out false information about the shooting of a terrorism suspect in the aftermath of the terrorist bombings in London in mid-2005 but who later turned out to be innocent, Guardian journalist Simon Hattenstone urges greater skepticism about official police accounts. After the shooting of Brazilian student Jean Charles Menezes, police claimed that he had been wearing an unseasonably bulky, padded jacket that might be concealing a bomb, and that he ran from police and vaulted a ticket barrier at a subway station before being shot dead. But closed-circuit TV footage from the subway shows him "entering the station at a normal walking pace and even picking up a free copy of the Metro newspaper. He was wearing a denim jacket." Hattenstone lists a series of other incidents in which British police have given false information about suspects who died in their custody. "Few deaths at the hands of the police have been as clear-cut as that of Jean Charles de Menezes," Hattenstone writes. "None has been as high profile. But the subsequent police distortion is all too familiar." 
- Simon Hattenstone, "We cannot take them at their word: 'Police sources' routinely vilify victims and excuse police actions", The Guardian (UK), August 18, 2005.