Conor O'Brien who has pleaded guilty to smuggling military-grade weapons for sale.

Conor O’Brien who has pleaded guilty to smuggling military-grade weapons for sale.

A Louth man who was part of a criminal organisation that imported military-grade firearms from America was selling them to “Ireland’s top criminals”, with pipe bombs and assault rifles that “can drop a deer at 900 yards” among the weapons being smuggled into the State.

“Without Conor O’Brien, there would be no criminal organisation, such was his importance,” said Detective Inspector Shane McCartan, telling the Special Criminal Court on Monday that O’Brien and his co-accused, Mark McCourt, were distributing guns and ammunition to criminal gangs in Derry, Armagh, Dublin and Limerick.