One proposal to reduce gun-related death and injury is the establishment of a register of prohibited persons – a “black list” of citizens suspected of mental instability or anti-social behaviour. These people could then be denied a firearms licence. Despite years of promotion by pro-gun lobby groups world-wide, no country or state has created such an additional register.

The main reason for rejecting this proposal is that even if every person with a history of mental illness and/or violent crime was locked away, about eight in ten future gun killers would remain at large.