What happens at a police station after a failed breath test in Northern Ireland?

The evidential procedure is more formal than the handheld roadside screening test. Northern Ireland legislation provides for two specimens of breath for analysis, with the lower alcohol reading used under the statutory scheme. Blood or urine can be required in circumstances set out by law, including where breath cannot properly be obtained or used.

Police will also deal with arrest, detention, interview and charging decisions in accordance with the circumstances. A person may be kept from driving until officers are satisfied it is safe and lawful to release them without an immediate risk of driving over the limit or while impaired.

If charged, the eventual penalty is decided by the court and depends on the offence, reading, previous convictions and surrounding facts.

The NI enforcement process separates screening from evidential proof. A roadside breath test, DrugWipe or impairment check gives police information and may justify arrest or further testing, but the prosecution is built from the statutory evidential procedure, officer observations and any laboratory or approved-device result. That distinction matters when reading reports of someone having “failed a roadside test”. The practical result is that at the police station you may be required to provide evidential breath specimens, or in specified circumstances blood or urine, and police will process the investigation using the statutory result. That prevents a rule written for Great Britain or the Republic of Ireland being applied automatically to a Northern Ireland case.