An Iowa man has been sentenced to 50 to 70 years in prison for sexually assaulting two boys between 2004 and 2012.

Robert Schuster, who turns 33 on Tuesday, pleaded no contest to first-degree sexual assault. He was sentenced Monday.

Authorities found seven other potential victims in addition to the boys Schuster is convicted of abusing.

Additionally Schuster has been sentenced to 10-to-30 years in prison in Iowa for assaulting two boys during overnight trips to his apartment in Council Bluffs. He’ll serve that sentence at the same time as the Nebraska one.

Lancaster County District Judge John Colborn says the long sentences reflect the seriousness of Schuster’s crimes and the need to protect the public.