Re: Reasonable excuse?

The magic words are "probable cause." The police are not supposed to stop someone unless they have probable cause to believe that a crime or violation of some sort is taking place. They might also have a right to stop someone if they are concerned for that person's health or safety, such as in a case where the person is having a seizure or is falling asleep or something like that.

It is also OK for the police to set up a screening road block and stop everybody.

But without one of those checkpoint type roadblocks, my understanding is that you are not to be stopped without probable cause. The definition of probable cause is essentially that a the existance of a crime or violation is more likely than not. It is a very low standard and doesn't take much.

What you are to do about this is a difficult question. It seems to me that the best bet is make sure everyone is legal to drive and say "thank you officer."

Re: Reasonable excuse?

Q: "1) do they have the right to follow you from the bar, without a reason, and pull you over?"

A: Following vehicles driving away from bars is a common police tactic, as they hunt for DWI suspects. But in order to lawfully stop a driver, they generally must be able to articulate reasonable suspicion of criminal activity or violation of traffic law, in order to justify the intrusion into the peace and liberty of the driver. Any traffic law violation is enough to justify a stop.

Q "2) Can they just give you a breath alyzer test without giving you any other field tests?"

A: The small portable breath machine police administer to drivers on the side of the road is commonly called a "PBT" device. Minnesota Statutes Section 169A.41, subd. 1 authorizes police to require a driver to blow into a PBT, essentially, if probable cause to believe that driver is in violation of listed alcohol-related driving offenses. If the police officer has that probable cause, and the driver refuses, the driver may be arrested for further alcohol breath, blood or urine sampling, and if that is refused, it may be forced and the driver can be charged with the crime of refusal of chemical "test." Police are not required to require the driver to perform any other so-called "tests," or field exercises. In any event, drivers are better off refusing to perform such roadside field exercises, since they are unscientific and police will almost always claim the person "failed" them.

Q: "3) After they have given you a breath alyzer test, and you pass. Can they just tell you to leave without giving you a reason why they stopped you in the first place?"

A: Yes, they can. You only have a right to be informed of the criminal charge or traffic violation allegation made against you, if one has been made against you. As a practical matter, it may be best to maintain a polite and civil attitude towards police officers, though there may be no need say much.

If you are feeling harassed by local police, rather than legal action, consider discussing the issue in a businesslike manner with local police chief, and local city council and county commissioners. Consider also talking informally with the officers involved, in a situation other than a traffic stop.