Oregon is urging the U.S. Supreme court to uphold the 112-year sentence given to a man who killed his parents before fatally shooting two students and wounding two dozen others at a high school 20 years ago.

The Oregonian/OregonLive reports 36-year-old Kipland Kinkel filed a petition in early August to the nation's highest court for a review of his sentence in the May 1998 shootings in Springfield, Oregon.

Oregon solicitor general Benjamin Gutman filed a brief this month in response, saying the sentence shouldn't be overturned because the Oregon Supreme Court found it reflected his "irreparable corruption rather than the transience of youth."

Attorneys Thaddeus Betz and Marsha Levick have argued their client never got the chance to demonstrate that he's not "permanently incorrigible" before the state imposed the sentence.