Wyoming federal prosecutors want an appellate court to keep a 35-year prison sentence for Andrew Silicani of Cheyenne who wanted to kill his adoptive parents for their insurance money and house totaling $850,000.

Silicani pleaded guilty in April 2015 to four identical counts of using the mail in a murder-for-hire scheme, and Chief U.S. District Court Judge Nancy Freudenthal sentenced him in July to 35 years imprisonment.

Court documents say he had a difficult upbringing including violence in elementary school, drug abuse, stealing, and threatening to harm his father.

He moved to Cheyenne at the beginning of the decade, soon committed a violent robbery, and was sentenced to a five- to seven-year prison term. He behaved poorly in state custody including a stint at the Casper Re-entry Center.

Silicani appealed the sentence to the Denver-based 10th U.S. Circuit Court of Appeals in December. His attorneys have argued that the district court should have ordered a mental evaluation for him and that his sentence is unreasonable.

However, federal prosecutors responded that nothing in the court record indicated his mental health issues caused him to violate the law, and in fact he behaved well in federal custody.

Silicani's sentence, which is far more than the minimum he could have received, also is reasonable in light of two stabbings in early 2011 and the murder-for-hire plot, prosecutors said. "'In short, Silicani has repeatedly showed utter disregard for the value of human life and suffering, whether his parents' or complete strangers'. Far from being capricious or whimsical, Silicani's 420-month sentence is reasonable under the totality of the circumstances."