Fears hard Brexit crash-out could hamper police in fight against crime in Northern Ireland
A member of the Policing Board has voiced concern that a "criminal justice nightmare" could follow if there is a no-deal Brexit.
The SDLP's Dolores Kelly spoke out after police chiefs warned that leaving the EU without agreement could leave them with severely diminished powers.
Deputy Assistant Commissioner Richard Martin, the national policing lead for Brexit, said police could be powerless to arrest foreign crime suspects on the spot if Britain loses access to European databases and agreements after Brexit.
Even when checks show an individual is wanted overseas, they could not be detained until a warrant is obtained from the courts, he said.
Mrs Kelly said: "Northern Ireland is unique, because we will have a land border with an EU frontier.
"I have been struck by the arrogance of Home Office officials who seem to think it will be alright on the night.
"They are under the impression that of course the EU will want to keep working with the UK, but cannot articulate the legal framework for doing so."
Mrs Kelly also expressed concern over extradition requests, which are expected to take longer if the UK is forced to rely on a 1957 convention in place of the current European Arrest Warrant.
"Lawyers will be running to question the circumstances in which their clients have been arrested," she added.
DAC Martin warned that a warrant would be needed from a UK court before a suspect wanted overseas could be detained.
He said that officers would have to run checks on the separate Interpol system, without access to existing EU tools.
"If that comes back with what they call a red notice, which is where somebody is wanted, we would then have to go to a magistrates' court to get a warrant to go and arrest that person," he explained.
"We could not arrest that person in front of us."
Checks on an EU national's criminal history could take as long as 66 days - which is 10 times longer than the current six day waiting time.
Mr Martin suggested that there would be a "real risk" individuals could abscond. "If they know they are likely to be incarcerated or charged, then I think that's a very real possibility," he said.
Under the terms of the agreement which was struck by Theresa May last year, both sides have committed to establishing a "broad" and "deep" partnership across law enforcement, criminal justice and security.
But UK agencies now face being locked out of databases which hold alerts about wanted individuals, DNA, fingerprints and airline passenger information.
A no-deal departure would force them to revert to alternative conventions, international policing tools and bilateral channels to trace missing persons and share intelligence.
"Every fall-back we have is more bureaucratic, it is slower," Mr Martin added. In the event of no-deal, UK authorities would lose access to tools including the Second Generation Schengen Information System (SIS II), which was searched by UK officers more than 500 million times in 2017.
Access to the European Criminal Record Information System, which documents tens of thousands of criminal convictions, could also be lost.
Asked whether the UK would be less safe, DAC Martin said: "Yes. I think there is a risk.
"Is the UK going to turn into criminal gangs running amok? No.
"I don't think we will become a country of choice for crime.
"Policing is not going to stop."
"We are going to build up the capability as best we can, but we will be much more limited than we currently are."