STURGIS, S.D. (KBHB) – The 17-year-old arrested in connection with the death of 16-year-old Shayna Ritthaler appeared in court Thursday for his arraignment hearing.

Michael Gavin Campbell, whose name was released because he is being charged as an adult, plead not guilty by reason of insanity to a first degree murder charge with an alternative of second degree murder.

Campbell can be convicted of either charge, but not both.

In court, Campbell calmly answered Judge Kevin Krull’s questions as to whether or not he understood the charges against him with a ‘yes, your honor.’

Judge Krull set Dec. 20 for the next status hearing and set that date as the deadline to turn in any documents related to the case.

Among those documents is a request to transfer the case from adult court to juvenile court.

Campbell’s Attorney, Steven Titus, spoke with the media after this morning’s hearing.

Campbell, if convicted, can face prison time, but cannot be sentenced to life in prison because he is juvenile.

Prosecutors allege Campbell shot and killed Shayna Ritthaler in his Blucksberg home earlier this month after an alleged argument between the two.

Ritthaler, from Upton, Wyoming, was the subject of a missing person’s case in the days ahead of the shooting. She was going to school in Moorcroft, Wyoming and was reported missing Oct. 3 after surveillance video showed her getting into a vehicle at Moorcroft Coffee Cup store. Her body was found Oct. 7.

Authorities are investigating how the two knew each other and what happened in the time before her death.