River Forest-Pit bull mixes attacked two women who were jogging in Dan Ryan Woods in separate attacks. The pit bulls seriously mauled 46 year old Mary Murphy-Smith and killed 48 year old Anna Cieslewicz. The pit bulls attacked the responding police officers in the forest preserve, and the police killed them.
The owners were never found.
Dogsbite.org describes how Anna's Law, which was named for Anna Cieslewicz, and was supposed to honor Cieslewicz by enacting protections for people from dangerous dogs, ended up a pet population control law.
CBS Evening News
Illinois Fatal Attacks