16:23The EssentialMore or Less: Violence, shootings and the police in the USBBC World Service Duration: 6 minutes Tue 19th Jul 2016, 16:23 on BBC World ServiceAvailable for over a yearListen nowTim Harford investigates the numbers surrounding police shootings in the USA. Show more GenresFactualScience & NatureFormatsMagazines & ReviewsBrandThe Essential Source: BBC Online