The Associated Press
FILE - This 2012 law enforcement file photo provided by the Wyoming Department of Corrections shows Andrew Silicani in Torrington, Wyo. On Thursday, July 9, 2015, a judge sentenced Silicani to an additional 35 years behind bars for trying to hire a hit man to kill his mother and stepfather while incarcerated. Lawyers for Silicani filed papers in federal appeals court in Denver on Monday, Dec. 21, 2015, claiming U.S. District Judge Nancy Freudenthal of Cheyenne should have sent him for a mental health assessment. (Wyoming Department of Corrections via AP, File)

CHEYENNE, Wyo. — A Wyoming man convicted of trying to hire a hit man to kill his parents is asking a federal appeals court to set aside his 35-year prison sentence and order a mental health review.

Lawyers for Andrew Silicani, 23, filed papers with the 10th U.S. Circuit Court of Appeals on Monday asserting that the sentence he received from U.S. District Judge Nancy Freudenthal in Wyoming this summer was too harsh. Silicani's lawyers argue the judge should have sent him for an evaluation given his long history of mental problems.

Silicani was serving time at the Wyoming State Penitentiary in Rawlins on two robbery convictions last year when, according to federal prosecutors, he tried to hire someone to kill his mother and stepfather in Cheyenne for insurance money.

According to an FBI agent's statement, a confidential source contacted staff at the Rawlins prison and reported that Silicani had asked if the source would be willing to kill Silicani's parents.

Another FBI agent began posing as the hit man and communicated with Silicani. According to court statements, Silicani told the agent he didn't want to pay more than $100,000 for what he called "demolition work."

Silicani expected to receive $850,000 in life insurance and property, according to court records. The confidential source told law enforcement that Silicani said he planned to buy "a Cadillac Escalade, clothes and jewelry."

Silicani pleaded guilty in April to four counts of using the mail in trying to hire someone to carry out the murders.

At sentencing this July, Cheryl Lambert, Silicani's mother, told Freudenthal the sentencing hearing was the saddest day of her life. Lambert also said she and her husband, John Ott, feared Silicani would try to kill them again if he ever were released.

"You are my son and I love you forever," Lambert said in court. "Now my real grieving begins as I learn to let go of you, my son and my only child."

Freudenthal said it was heartbreaking that Silicani would try to kill his mother after she had tried to support him through a lifetime of mental problems.

According to the Wyoming Department of Corrections, Silicani was paroled from his state sentence in October and began serving his federal sentence. According to a U.S. Department of Justice Web site, he's housed at a federal prison in Colorado.

Lawyers with the Federal Public Defender's Office are representing Silicani on appeal. An attempt to reach a lawyer on his team for comment Tuesday was not immediately successful.

In their brief, Silicani's lawyers state that Freudenthal imposed a harsher sentence than the maximum of just over 24 years indicated by federal sentencing guidelines.

"On balance, the need to protect the public and to punish Mr. Silicani weighed too heavily in the district court's sentencing decision, which unduly discounted Mr. Silicani's documented history of mental illness and the need for the sentence imposed to avoid unwarranted sentence disparities," Silicani's lawyers stated.

The U.S. Attorney's Office in Cheyenne prosecuted Silicani. John Powell, spokesman for the office, declined comment Tuesday on the appeal.