Biography
Frank Krueger was serving a life sentence according to the Wisconsin report.
The Wisconsin report explicitly states that Frank and LeslieKrueger were serving life sentences at Waupun. It separately lists Caroline and LouisKrueger as on bond, preventing a collective life sentence from being assigned to all four. Source: https://www.govinfo.gov/content/pkg/SERIALSET-07987_00_00-063-0159-0000/pdf/SERIALSET-07987_00_00-063-0159-0000.pdf#page=74