A “bad arrest” occurs when an officer arrests someone based upon a “mistake of law.” A mistake of law, no matter how reasonable, can never merit an arrest based upon probable cause. In Chanthasouxat, an officer stopped a vehicle because the vehicle did not have an inside rear view mirror which the officer thought was required by law. During the search of the care, cocaine was found.

The evidence was not allowed to be used because it was deemed to be acquired from an illegal arrest and search. The excluded evidence included statements that were made by the defendants while seated in the rear of the patrol car.

However, a mistake of fact will not prevent an officer from successfully admitting evidence into court. The question comes down to whether the officer’s mistake was reasonable.