Independent charity Crimestoppers is offering a reward of up to £10,000 for information leading to the arrest and conviction of those responsible for the murder of a prison officer in Northern Ireland.
David Black was gunned down on his way to work in a motorway ambush yesterday.
This heinous crime has sent shockwaves through communities across Northern Ireland and left a family without their father.
I am urging anyone with information about this crime, no matter how small that information may be, to contact Crimestoppers anonymously - we don't want to know who you are, only what you know.
Three men, aged 31, 29 and 44, have been arrested following the killing of prison officer David Black in Northern Ireland.
Leaders in Northern Ireland have condemned the "horrific" motorway murder of a veteran prison officer by suspected dissident republicans.