Death of girlfriend : I ' m glad justice finally came -- before he killed my daughter '' Drew Peterson arrested in the slaying of his third wife , Mary Ann . Renewed interest in Savio 's death came after Peterson 's fourth wife disappeared . Dobrich said Peterson cooperated with police during his arrest . Peterson , through his attorney , denies any involvement in either case .
Death of girlfriend : I ' m glad justice finally came -- before he killed my daughter '' Drew Peterson arrested in the slaying of his third wife , Mary Ann . Renewed interest in Savio 's death came after Peterson 's fourth wife disappeared . Peterson , through his attorney , denies any involvement in either case .