More than 112,000 Illinois residents have lost the right to own guns. The state doesn’t know if 84,000 still have them, sheriff says.

More than 112,000 Illinois residents have been deemed too dangerous to own guns, but the state doesn’t know if 84,000 of those people still have them, according to a new analysis by the Cook County sheriff’s department.

The number lays bare a public safety risk that authorities have warned about for years, as the state remains unable to ensure that people surrender their weapons after their firearm owner’s identification cards have been suspended.

And despite several deaths at the hands of gunmen with revoked FOID cards...