WILLMAR (AP) - The attorney for a Willmar teenager charged in his grandmother's killing wants a judge to suppress part of his client's statement to law enforcement.

Attorney Daniel Mohs argued Friday that Bureau of Criminal Apprehension agents who questioned 18-year-old Robert Warwick did not advise him of his Miranda rights after telling him that he was under arrest.

Warwick's grandmother, 79-year-old Lila Warwick, was slain during a robbery in her Willmar home on July 29.

Robert Warwick and 19-year-old Brok Junkermeier have been indicted on first-degree murder charges. Warwick allegedly masterminded the crime, suspecting his grandmother had more than $40,000 in a safe. Junkermeier allegedly stabbed and strangled her after making her write him a check.

Judge David Mennis will rule after attorneys have filed briefs.