It should come as no surprise to anyone that criminals will seek to take advantage of the porous border between Northern Ireland and the Republic. With 300 crossing points along the 310-mile frontier, it is impossible to police effectively - as was shown during the Troubles.
PSNI Chief Constable Simon Byrne spelled out to MPs on the NI Affairs Committee the potential consequences after Brexit, and it makes uncomfortable reading.
He argued that criminals would see the border as the soft underbelly of the Common Travel Area and ripe for exploitation in the smuggling of guns, drugs and people. With 80 organised crime gangs in the province, 16 with a presence spanning the border, the threat is both obvious and viable.
The UK's exit from the EU will mean a loss of access to European Arrest Warrants and also reduced cooperation with other European police forces.
However, with Garda Commissioner Drew Harris being a former Deputy Chief Constable of the PSNI, cross-border cooperation should be enhanced, which is a ray of hope.