The device at the police station works no differently than the roadside one. It is just considered more accurate in that it gives a number value to represent the estimated percentage of alcohol in your blood, based on the concentration of VOCs in your breath that have methyl groups. Roadside only does pass/fail/warn. The only way to actually know what is present in your system is a blood test. People don’t normally get breathalyzers unless there is a reason for it, even at RIDE checkpoints so yes, we may introduce a possibility of incriminating someone based on the results of a breathalyzer test alone. Unless we just stick to probable cause.