OGDEN -- Lawyers for Matthew David Stewart, accused of gunning down a police officer during a pot raid at his Ogden home, are challenging Utah's death-penalty law.
Weber County prosecutors said they will seek the death penalty if Stewart is convicted of aggravated murder and other charges.
The defense lawyers, including Randy Richards, recently filed a motion saying Utah's law is unconstitutional because it leaves juries with no choice but the death penalty in cases of aggravated murder.
In court papers, lawyers conclude: "... the defendant respectfully requests this court to find that the sentencing scheme ... violates the due process clause of the Utah and the United States Constitution in that it requires a defendant, once convicted of aggravated murder, to meet a standard that is impossible to meet in order to avoid a sentence of death as set forth in that statute."
"Specifically," it continues, "given the nature of the aggravation of a murder, trying to establish that there are one or several mitigating factors that somehow outweighed the enormity of the murder is impossible, and therefore violative of the due process claused of both constitutions."
Also in the court papers, the lawyers refer to Stewart as a youthful defendant with no criminal history who was under mental or emotional duress.
Stewart's family said the 38-year-old Army veteran was growing marijuana to ease his anxiety and depression. Stewart told investigators he believed he was being robbed when a narcotics task force broke into his house on Jan. 4, 2012.
In November, Stewart entered not guilty pleas to all charges from the Jan. 4 shootout at his home that left one police officer dead and five others wounded.
Stewart faces the death penalty if convicted in the death of officer Jared Francom.
He is also charged with seven counts of attempted aggravated murder for allegedly shooting at seven other officers, hitting five, plus one count of second-degree felony cultivation for the 16 marijuana plants taken from his home after the shootout.
The Associated Press contributed to this article.