CASPER — A Wyoming man who more than 30 years ago kidnapped, raped and murdered a teenage woman asked this week for the U.S. Supreme Court to review his case, arguing that his mental competency to stand trial was not properly determined in lower courts. 

The request is the latest in a series Dale Wayne Eaton, 75, has made of the appellate system since his 2004 conviction for crimes committed in 1988 against Lisa Marie Kimmell, who disappeared during a drive from Colorado to Montana. 

Although Kimmell’s body was found in the North Platte River shortly after the killing, the case went cold and prosecutors did not charge Eaton for 15 years. Following his trial, Eaton was sentenced to death. 

After a federal judge vacated Eaton’s sentence, prosecutors announced last year they would again attempt to put Eaton to death. An anticipated sentencing hearing in Natrona County District Court is now on hold, as Eaton appeals to the country’s highest court. 

In the latest filing, Eaton asked the Supreme Court to review his case, arguing that a lower court finding was incomplete when it determined that Eaton’s court-appointed trial lawyers did not provide him effective assistance. 

Appellate courts have already found that Eaton was not properly assisted during the phase of his trial that resulted in his death sentence. 

However, in the latest request, Eaton’s lawyers argue that none of the lower courts have fully determined whether his trial lawyers harmed his case by failing to investigate his competence before the trial began. 

Eaton’s appellate team — led by Sean O’Brien, a Kansas City law professor — asks in the 39- page filing for the U.S. Supreme Court to determine whether lower courts should have examined new evidence of Eaton’s mental illness in deciding the issue. 

In support of their request, Eaton’s appeals lawyers attached an affidavit from the doctor who found Eaton competent for trial stating that more recent findings are consistent with a number of mental illnesses. 

That affidavit, Eaton’s lawyers argue, would have been used to consider an altogether new claim of ineffective assistance of counsel in appeals circuits other than the 10th U.S. Circuit Court of Appeals, which determines application of federal law to Wyoming and other states in the region. 

The appellate team argues that discrepancy merits a review by the Supreme Court. 

Although authorities began investigating Kimmell’s death shortly after her body turned up in the North Platte River, investigators were unsuccessful for a decade. 

In 1998, after Eaton was convicted of assault and sent to the Wyoming State Penitentiary, authorities found Eaton’s DNA linked him to Kimmell’s body. 

In 2002, authorities unearthed Kimmell’s car on Eaton’s property in Moneta, about an hour from Casper. 

In 2003, the Natrona County District Attorney’s Office charged Eaton with Kimmell’s death, and in early 2004 jurors convicted him of first-degree premeditated murder, felony murder, aggravated kidnapping, aggravated robbery and first-degree sexual assault. Days later, the jury found Eaton should be put to death. 

It was in 2014 that a federal district court judge found in favor of Eaton, staying his execution and ordering a new sentencing hearing. Then, last year, the circuit court upheld that ruling and declined a request from Eaton to keep prosecutors from again seeking a death sentence. 

In August, Natrona County District Attorney Dan Itzen filed paperwork with the state court indicating he would seek capital punishment in the case.