CREATORS
May 19, 2026
Why would
material evidence in the possession of a murder suspect be inadmissible at
trial?
Simple —
the exclusionary rule. The recent decision by Judge Gregory Carro of the New
York Supreme Court in the Luigi Mangione prosecution has spurred interest in
what the exclusionary rule does and if it is still needed.
The rule
was first established in federal court in 1914. The U.S. Supreme Court ruled
that federal law enforcement officers could not use evidence obtained in
violation of a suspect's Fourth Amendment rights in federal criminal trials.
Prior to 1914, law enforcement officers, although compelled by the U.S.
Constitution not to violate an accused's rights, could nonetheless violate
those rights with impunity.
The state
version of the rule didn't come about for another 47 years. I wrote about the
exclusionary rule for Creators in 2025, and it is worth reexamining. In 1957,
Cleveland, Ohio, police officers went to the home of Dollree Mapp looking for a
suspect in a criminal investigation. She refused to let the police in without a
warrant.
The police
left, and when they returned, they were armed with a "fake" warrant.
Chicanery took the place of real police work. Instead of going to a judge to
get a warrant, the police drew up their own. After entering Mapp's home, police
conducted a search and confiscated obscene material, resulting in Mapp's
arrest.
As a
result of the police misconduct, the U.S. Supreme Court provided a remedy — the
exclusion of illegally obtained evidence from admission in a criminal
prosecution — resulting in a dismissal of the charges.
Many
Supreme Court observers suggested that the Mapp decision would be detrimental
to law enforcement. The courts would be inundated with challenges and the
guilty would go free in droves. That never happened.
What the
exclusionary rule accomplished was a higher standard of police training and, in
turn, police work. Ironically, the late Justice Antonin Scalia cited
"increasing professionalism of police" as a reason for the
exclusionary rule's obsolescence.
Scalia's
argument didn't make sense then and doesn't make sense today. Without the
exclusionary rule, an individual's constitutional rights would be ignored. Law
enforcement training would turn on a dime.
For now,
the exclusionary rule is still around. Mangione's case is illustrative of why
it is still needed. There was a nationwide manhunt for Mangione after the
brazen assassination of insurance executive Brian Thompson on a New York City
sidewalk. Mangione was recognized by a McDonald's Restaurant employee in
Altoona, Pa.
The police
were called and Mangione was detained after they arrived. Mangione had a
backpack that was moved to a table approximately nine feet away. He was patted
down for officer safety, both of which are appropriate under the Fourth
Amendment.
However,
the police went further and searched his backpack without obtaining a search
warrant. They said they needed to make sure there was not a bomb in the bag.
Prosecutors argued that the circumstances created an exception to the rule
requiring a warrant. The court didn't buy it. Judge Carro ruled that the search
of Mangione's bag at McDonald's violated his constitutional rights.
As a
result, by way of the exclusionary rule, evidence including a gun magazine, a
cellphone, a passport, a wallet and a computer chip, all found in the backpack,
is not admissible at trial.
However, a
second search of the bag at the police station revealed a gun linked to the
crime and Mangione's manifesto attacking the insurance industry. The second
search of the same bag without a search warrant is constitutionally
permissible. The police may conduct a warrantless inventory search to record
the suspect's belongings. As a result, the gun and manifesto are admissible at
trial.
The
exclusionary rule promotes integrity in the criminal justice system — even
strong evidence of guilt, in a high-profile killing, cannot be used if police
violate the Constitution to get that evidence.
Matthew T.
Mangino is of counsel with Luxenberg, Garbett, Kelly & George P.C. His
book, "The Executioner's Toll," 2010, was released by McFarland
Publishing. You can reach him at www.mattmangino.com and follow him on Twitter
@MatthewTMangino
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