The Department of Justice on Friday curtailed a federal program that allowed police to seize and keep cash, cars, and other private property without evidence of a crime, the Washington Post reported. Local and state police will no longer be able to seize and keep private assets through the federal program unless they're working with federal authorities or the assets are directly linked to public safety concerns.

Items that can still be "adopted" by local and state departments working alone include firearms, ammunition, explosives, and property associated with child pornography. But the change could affect less than 15 percent of the federal Equitable Sharing Program, prompting some advocates to caution more reform is still needed. Police have been heavily criticized for using the program to seize people's assets without evidence of a crime and pocketing the proceeds to fund their own departments.

The change places a big check on police power

The federal program, expanded through the war on drugs, allowed local and state police departments to seize private property allegedly used for criminal purposes, even without evidence of a crime, and share the proceeds with federal agencies. Police would keep up to 80 percent of the proceeds, while federal agencies claimed the rest.

(Read more: Why Eric Holder's civil forfeiture reforms can't keep police from taking your stuff.)

States still allow police to seize private assets, but some of the state laws are more limited and force at least some of the proceeds to go to a state's general fund — instead of the police departments themselves.

Critics of the federal program said it created an incentive for police to unnecessarily stop and search people, since the seizures could be used to fund their own departments. A previous Washington Post investigation found police routinely seized property without any evidence of wrongdoing.

A government official speaking to the Post anonymously said Attorney General Eric Holder "believes that the new policy will eliminate any possibility that the adoption process might unintentionally incentivize unnecessary stops and seizures."

The libertarian Institute for Justice praised Holder's decision in a statement. But the group also criticized what the change leaves out: "[S]tate and local law enforcement can still partner with federal agents through joint task forces for forfeitures not permitted under state law, and state and local law enforcement can use such task forces to claim forfeiture proceeds they would not be entitled to under state law. Moreover, the federal government can still pursue its own civil forfeiture actions, where property owners face very significant burdens. And the policy does not change state forfeiture laws, many of which burden property owners and permit policing for profit."

Further reading: How police can take your stuff, sell it, and pay for armored cars with the money.