Evan Fitzgerald was on bail for gun charges when he entered a Carlow shopping centre yesterday and fired shots, before fatally shooting himself.
Last year, he was caught with guns and ammunition which he admitted to having bought on the 'dark web', a part of the internet where users operate through anonymity.
But, what is the dark web, how common is it to buy guns here, and what can be done about it?
Joining Kieran to answer some of these questions is Cyber Security Expert, Ronan Murphy, Chief Strategist for Forcepoint and Chairman of SmartTech247.
