Posting and enforcing illegal speed limit signs is a clear-cut case of deliberate-deception from start-to-finish. The Selectmen manufactured and proffered prima facie evidence of phony speed limits and bogus Speeding citations, and then concealed exculpatory evidence. This conduct is sufficiently outrageous, unjustified, and ubiquitous as to “shock-the-judicial-conscience” and state a substantive due process claim. See Cnty. of Sacramento v. Lewis.
The substantive due process clause clearly forbids convictions predicated on deliberate deceptions. After all, “[t]he function of law enforcement is the prevention of crime and the apprehension of criminals. Manifestly, that function does not include the manufacturing of crime.” Sherman v. United States; See Limone v. Condon (fabrication of evidence “necessarily” violates due process); Surprenant v. Rivas (fabricating false charges limns a constitutional violation); Burke v. Town of Walpole (trooper failed to communicate exculpatory evidence); Haley v. City of Boston (deliberate police concealment of material evidence unarguably implicates a defendant’s due process rights).
In Petition of Sharpe, the Supreme Judicial Court held that permitting a traffic offense to stand if the traffic signals were not lawfully maintained would “shock the judicial conscience.” Four years later, the Supreme Court used the identical terminology when it formulated and first applied the shocks-the-conscience test for substantive due process. Rochin v. California. Both courts clearly appreciated the existential threat that, “[n]othing can destroy a government more quickly than its failure to observe its own laws, or worse, its disregard of the charter of its own existence.” Mapp v. Ohio (defending the exclusion of illegally obtained evidence).