A divided Iowa Supreme Court banned police from searching through people’s uncollected trash without a warrant on June 18. The decision outlaws an investigative technique that has been used by law enforcement for decades.

The 4-3 ruling determined that if officers search for evidence of crimes in trash left outside people’s homes, they are violating that person’s rights and committing an unreasonable search and seizure. It also overturned a 1988 Supreme Court ruling long adhered to by state law enforcement that found that the U.S. Constitution’s Fourth Amendment does not ban investigators from sifting through garbage outside one’s home in pursuit of evidence.

The question arose after a Clear Lake man was arrested on suspicion of dealing drugs after an officer found drug-related evidence in his trash. The officer apparently rummaged through the man’s trash in a public alley outside his home and found items that tested positive for morphine and cocaine, as well as several pounds of poppy seeds.

The officer used that information to obtain a search warrant, and police found a small amount of marijuana and Vyvanse, a prescription drug that he lacked a prescription for. The man was ultimately convicted of misdemeanors and was sentenced to two days in jail.

Justice Christopher McDonald wrote for the majority that although the tactic may be useful and expedient, it is still an unconstitutional trespass of private property. He added that if cities have laws banning residents from accessing each other’s trash, then the same should go for law enforcement.

“We do not question the utility of warrantless trash grabs for the purposes of law enforcement, but the utility of warrantless activity is not the issue under our constitution. He added that “garbage contains intimate and private details of life.”

According to ABC News, under the new ruling, Iowa joins Oregon, New Hampshire, Vermont, Washington, New Mexico and New Jersey in limiting trash searches through their state constitutions.

The decision affected two cases where people were convicted of drug crimes based on evidence collected from trash searches. Because of the Iowa court ruling, the cases will be sent back to lower courts to decide whether to throw the cases out altogether.

Dissenting justices warned that the decision went against the majority of states and outlawed a useful tactic to gather evidence of drug manufacturing and dealing. They argued that people relinquish control over their property and could not expect to have privacy when they put their trash on the curb.

They also called the majority’s reasoning nonsensical because it calls into question the legality of several other law enforcement practices.

Christensen said the reasoning could lead down a rabbit hole of future legal challenges against officers who make warrantless traffic stops, search private property and seize guns under emergency or other circumstances that have long been allowed by courts.

“Unfortunately, our state law enforcement officials are now left with a guess-and-see approach to many actions previously considered lawful, undermining public safety in the process,” Christensen wrote.

Dissenting Justice Thomas Waterman said trash searches can help shut down meth labs and other “societal scourges.” He said banning them in state investigations would lead to more federal drug prosecutions, which carry longer prison sentences.

“Offenders facing federal time without parole likely won’t view today’s decision as advancing their civil liberties,” he said.