Dissident republicans say Brexit border controls will see return to violence
Brexit poses challenged to the Irish border that could see a return to the bad old days
Earlier this year, the city of Derry made global headlines when the brilliant young journalist Lyra McKee was shot dead by a group calling itself the New IRA.
During a night of rioting in Creggan, a young man fired a handgun at police lines and Lyra was killed.
Paddy Gallagher is a spokesperson for Saoradh, a small republican party seen as the New IRA's political wing - something they deny.
He believes a no deal Brexit could provide a justification for dissidents to renew their armed struggle.
Paddy insists that his party has nothing to do with political violence, but the inside of Saoradh's office is like a shrine to the IRA.
This level of support for republicanism is to be expected from an organisation that has "Join the IRA" written on the side of its office but presents a very real problem for Border Force and the police.
In the event of a no deal Brexit, and resulting border infrastructure to control the flow of goods and people, they are the staff who could become targets.
"Armed struggle continues to exist," Gallagher says. "It's not something that doesn't happen anymore. There are still women and men that are willing and capable of carrying out acts of armed resistance against the British state.
"I can only assume, judging by history, that their focus would be manned or fixed British installations on the border."