The decision will not halt civil forfeitures, said Wesley P. Hottot, a lawyer with the Institute for Justice, which represented the Land Rover’s owner.

“People are still going to lose their property without being convicted of a crime, they’re still going to have their property seized,” Mr. Hottot said. “The new thing is that they can now say at the end of it all, whether I’m guilty or not, I can argue that it was excessive.”

Law enforcement agencies have resisted efforts to curtail civil forfeiture, saying they rely on the proceeds for sorely needed equipment. It is difficult, if not impossible, to calculate the total value of civil forfeitures by local police departments and prosecutors, but a significant portion comes from joint operations with federal law enforcement and is tracked by the Justice Department.

In fiscal year 2018, state and local agencies received $400 million through this arrangement, known as equitable sharing. The amount varied widely by agency — the Surprise Police Department in Arizona received $570,000, while the Buffalo Police Department in upstate New York got $130,000. The New York Police Department took in $7.8 million.

In Philadelphia, forfeiture proceeds once accounted for 20 percent of prosecutors’ budget, while agencies in New York and California tended to take in the highest sums, according to the Institute for Justice.

Investigations across the country have uncovered many examples where the property seized was disproportionate to the crime, taken from innocent citizens or targeted in accordance with law enforcement wish lists. As its name suggests, a civil forfeiture does not require a criminal conviction or even criminal charges but only proof that the property at issue was used in connection with a crime. Owners who wish to reclaim their property must demonstrate that it was not, or that it was used without their knowledge.

A recent series of articles by the Greenville News examined every civil forfeiture case in South Carolina from 2014 to 2016, finding examples like that of Ella Bromell, a 72-year-old woman who had to fight off the forfeiture of her home after drug dealers conducted transactions on her property, despite Ms. Bromell’s multiple attempts to stop them.