Section 42(2)(o) of the "Act" establishes the length of time to be served in custody or in community supervision for cases of attempted murder, manslaughter, aggravated sexual assault. The total serving time for these periods cannot exceed 3 years since life imprisonment is imposed on adults responsible for these offences. Under the "Act", murder is the only offence that must result in a custody and supervision order. The maximum serving time is 10 years for first-degree murder and 7 years for second-degree murder.