We learned a few years ago in Heien v. North Carolina, 574 U.S. 54 (2014), that the exclusionary rule does not apply to the fruit of a police seizure based on an objectively reasonable mistake of law.
But what about an earnestly believed mistake of law?
If that belief is not objectively reasonable, then it cannot support the seizure.
So held D. Kan. Judge Teeter in a recent order suppressing the fruit of a traffic stop for leaving a running car "unattended." "Unattended" as used in the Topeka ordinance at issue does not apply to a car that is simply "unoccupied" while its driver remains nearby. The seizing officer's earnest belief to the contrary was not reasonable. Applying the exclusionary rule in this circumstance will deter "a sloppy study of the laws" that officers are duty-bound to enforce.