A law that brings in millions of dollars for law enforcement in Kansas and Missouri could soon change.

Under a law called civil asset forfeiture, a traffic stop could end with someone losing their car or life savings. Wednesday, the Supreme Court of the United States heard a case from Indiana that looks at the law.

It centers around a man named Tyson Timbs who sold undercover police in Indiana $400 worth of heroin.

He was arrested, and they took his $40,000 Land Rover through asset forfeiture.

On Wednesday, during oral arguments, his attorney told the Supreme Court that the seizure was an excessive fine, which is banned by the Constitution. The case matters because law enforcement in Kansas and Missouri uses asset forfeiture often, and it generates a significant amount of money.

(Read more: KMBC)