Indiana’s voter roll purge system is on hold after a federal judge temporarily halted it.

The judge’s ruling says the state's method to delete voters from its registration lists likely violates federal law.

Federal law says there’s two ways to delete a voter from the rolls: the voter asks to be removed or the voter fails to respond to mailed notifications and doesn’t vote in two, separate federal elections.

Voter advocacy groups sued the state over an Indiana law that allows counties to immediately eliminate voters from the rolls if they match up to registrations in other states. Those matches are made principally through a multi-state voter registration database known as Crosscheck.

The state argues its use of so-called “confidence factors” to determine whether a voter registration matches – like Social Security number and date of birth – is enough to satisfy federal law. Judge Tanya Walton Pratt calls that reliance “misplaced.” And she dismisses the state’s argument that a voter’s registration in another state notifies Indiana they want their registration eliminated.