Defense attorney Steven Mottinger told Supreme Court justices that authorities conducted illegal searches of Wacht's van and home.

The North Dakota Supreme Court is considering the appeal of a man serving life in prison for shooting and beheading a North Dakota State University researcher.

The Forum newspaper reports (http://bit.ly/14LKrkG ) that attorneys made oral arguments in the appeal on Monday. Justices will rule later.

Prosecutors said 32-year-old Daniel Wacht shot Kurt Johnson after a night of drinking on New Year's Eve 2010, then cut off his head. Authorities found Johnson's head in Wacht's basement but the researcher's body has not been found. A jury convicted Wacht of murder a year ago.

Defense attorney Steven Mottinger told Supreme Court justices that authorities conducted illegal searches of Wacht's van and home. Prosecutor Marina Spahr said there was a "multitude of facts" supporting the trial judge's decisions and the guilty verdict.