SPECIAL REPORT:

Mistakes the police make . . . and how they can help you:

Stopping a vehicle on the basis of an anonymous call. An officer cannot rely on a phone call to stop you, if he does not observe poor driving independently.
Following a driver into his residence without an invitation or without enough information to justify the entry. Your home is protected under the Fourth Amendment.
Basing an arrest on the statements of the driver alone. The officer must have independent evidence to corroborate these statements. This often arises when he has not seen you in physical control of your car.
Detaining a driver longer than is reasonable to investigate. The constitution does not allow officers to hold you without limit.
Stopping a vehicle without an articulable suspicion. An officer may not stop you just because he thinks you are suspicious.
Stopping a vehicle because it stops in the middle of the street or it is driving too slow. Unless there is a specific traffic ordinance you are violating, such as impeding traffic, it is not lawfull for an officer to stop you.
Weaving within a lane. The statute only requires you to drive as nearly as is practible within a single lane. Some cases hold that one weave into the shoulder is not enough reason for a stop.
Stopping a vehicle based on a misperceived violation of a law. The officer must be right about his interpretation of the law.
Stopping a vehicle for an improper sign. Street signs and lane markings must comply with the Manual for Uniform Traffic Control Devices.
Failing to follow the rules of the Department of Health and Intoxilyzer operation manual. These failures may invalidate any alcohol testing.
Stopping at an improper roadblock. There are guidelines that must be followed to validate the stop.
Stopping a vehicle just to check the driver's license and registration. There must be an actual traffic violation or an articulable suspicion of a crime.
Stopping a vehicle without being able to identify it as the one actually committing a traffic infraction. Officers must be able to convince the Court that they stopped the right car.
Stopping a vehicle for no reason at all. It's done. Officers usually do not show up in Court on these.
Blocking a vehicle's exit without justification. Officers may not restrict a drivers freedom to leave without a reason.