In 2000 a row over a failed drugs deal ignited a murderous feud in Dublin's south inner city. The Crumlin-Drimnagh feud's first victim was a friend of Thompson's and he led his Crumlin crew in a series of tit-for-tat killings. Sixteen young men would lose their lives over the next fifteen years.

Meanwhile, childhood friend, Daniel Kinahan, had become a senior figure in his father Christy Kinahan's international crime cartel. Working with the Kinahan Cartel Thompson launched himself as a drugs dealer in Dublin.

When another deadly feud broke out in 2016 — between the powerful Kinahans and veteran Dublin criminal, Gerry 'The Monk' Hutch — Thompson was ready to get his hands dirty. But Thompson's loyalty would be his undoing. In August 2018 he was convicted of murder and jailed.