The firearms licensing regime is based on trust and confidence between police and Certificate Holders. A substantial portion of that confidence comes from the police’s ability to review an applicant’s past behaviour and reassure themselves that this is likely to indicate responsible behaviour going forward.
In an ideal world information and intelligence relating to criminality might be shared freely between law enforcement organisations. But we are not there yet.
It’s therefore not unreasonably that police might expect additional reassurance from applicants who have spent considerable time outside the UK.
