CHICAGO (CBS) — Immigrant rights activists won a victory in Cook County Wednesday, as the County Board agreed to free illegal immigrants being held on lesser charges.

As WBBM Newsradio’s Lisa Fielding reports, when federal authorities arrest illegal immigrants, they are jailed in Cook County. But it is up to the local government to pay for their detention.

LISTEN: WBBM Newsradio’s Lisa Fielding reports

County Board President Toni Preckwinkle says the new ordinance ends this practice.

“This is a great step forward toward a more fair policy,” she said.

Under the ordinance, illegal immigrants being held on misdemeanor charges will be released, despite federal requests to the contrary. It follows a federal judge’s ruling in Indiana that U.S. and Immigration and Customs Enforcement detainers in local jails are voluntary, rather than mandatory, the Chicago Tribune explained.

“This is about serving our taxpayers better, and ultimately, this is about keeping families together,” Preckwinkle said.

During debate on the ordinance Wednesday, some commissioners warned that hardened criminals could end up on the streets as a result.

Commissioner Timothy Schneider (R-15th) called it the county’s “Willie Horton moment,” the Tribune reported. Horton was the Massachusetts prisoner who escaped during a weekend furlough and committed assault, armed robbery and rape, in a scandal that became a campaign issue in the 1988 presidential race in which George H.W. Bush defeated former Massachusetts Gov. Michael Dukakis.

But in the end, county commissioners voted 10-5 to end unfunded mandates by federal authorities. Preckwinkle says the new law will save taxpayers more than $15 million per year.