The commissioner of the Metropolitan Police has suggested that Britain's departure from the European Union will be costly and could have a damaging effect on public safety.
Cressida Dick told the BBC on Thursday that the adjustment to leaving the EU would be more challenging if there's no deal in place between Britain and the bloc.
She says U.K. police will have to work out access to vital databases and will need new procedures so people can still be quickly arrested and extradited despite Brexit. Dick says that would be "very difficult to do in short-term" if Britain has no transition deal.
The commissioner hopes Britain will have systems like the ones in place now to facilitate fighting crime.
Prime Minister Theresa May has agreed upon a Brexit deal with EU leaders but many British lawmakers don't like it.