Jeffrey Handley was convicted on 58 charges including rape, sodomy and sex abuse.
Police said he assaulted and sexually abused a family member beginning when they were 7-years-old.
Oregon State Police became aware of the abuse back in May. A day later, troopers said Handley shot himself in the head with a .22-caliber rifle at his home.
Prosecutors had asked for a longer sentence as 25 years was the minimum amount prescribed for the sexual abuse of a victim under the age of 12.