Formal definition for "with reasonable cause"

Jambonjunior

Has reasonable cause ever been formally defined?

Section 23 Misuse of Drugs Act, 1977
 "A member of the Garda Síochána who with reasonable cause suspects"

I'm coming from the All Together Now festival thread where people said they were stopped and searched coming and going from there cars in the festival e.g. the reasonable cause was being at a music festival. Is that enough? Does the reasonable cause have to reach a certain level or is it purely trusting their judgement?

Peregrinus

There isn't a one-size-fits-all definition of phrases like "reasonable cause". The whole point about such phrases is that they are a bit elastic, can be adapted to different circumstances and allow some scope for balancing competing priorities. What might be a reasonable cause for looking in the boot of your car, and the glove box, might not be a reasonable cause for conducting a cavity search on you personally. What might a reasonable cause when you're looking for a kidnap victim whose life is in danger might not be a reasonable cause when you're lookin for a joint. Etc, etc.

That's not to say that the phrase has no content at all. Your reasonable cause must be based on what you knew at the time — you can't retrospectively manufacture a reasonable cause for the search based on the fact that you found something incriminating. It has to be based on objective facts, not just a hunch or a prejudice or stereotyping of people based on age, ethnicity, etc. The more gross the infringement on constitutional rights, the stronger the facts need to be — e.g. it's more demanding to construct a reasonable case for searching a house than it is for searching a car, since the inviolability of the dwelling is constitutionally guaranteed.

There is a 2009 case (Farrell) which holds that "knowledge of a general drugs problem in the area" is not a reasonable grounds for searching a car. This isn't quite the same, though, because we're not talking about an area that a car happens to be in, but a specific event that the people in the car will be attending. And, we don't know this but it's possible that the guards had intelligence about the supply of drugs at that event which fed into decisions about searches. On the other hand, it's possible that they didn't.

The matter would most likely only come before a court if the search actually found something — it might be drugs, it might be an offensive weapon — and charges were laid as a result. The defendant would then challenge the admissibility of the evidnence about finding the drugs/the knife on the grounds that it was illegally obtained, and then the guards would have to justify their "reasonable grounds" for conducting the search.