ALGONA, Iowa — A Minnesota teenager charged with killing two convenience store clerks in Iowa plans to use the insanity defense.

The Des Moines Register on Wednesday says the insanity defense is in court documents filed in Kossuth County.

Seventeen-year-old Michael Swanson, of St. Louis Park, Minn., is charged as an adult with murder and robbery and Kossuth and Humboldt counties. He’s accused of killing a clerk in Algona on Nov. 15, then driving to Humboldt and killing another clerk.

Swanson’s attorney, Charles Kenville, asked a Kossuth County judge to combine the murder trials, set for this summer. Kenville withdrew a motion to transfer the Kossuth County case to juvenile court. A judge denied a request to transfer the case in Humboldt county to juvenile court.

Kenville declined to comment on the filings.