Attorneys for the man charged in the deaths of four University of Idaho students have alleged police misconduct and flawed search warrants.

Bryan Kohberger and his attorneys will argue at hearings this week for excluding a host of evidence in the homicide case that is heading toward a summer trial.

Utah is the only state to have used firing squads in the past 50 years, according to the Death Penalty Information Center. Idaho’s neighboring state executed Ronnie Lee Gardner in 2010 by firing squad. Mississippi, Oklahoma and South Carolina also permit use of the firing squad as an alternative to lethal injection.