SIDNEY, Mont. -

A state psychiatrist says a Colorado man seeking to avoid trial in the killing of a Montana teacher manipulated other patients and was duplicitous with staff at Montana State Hospital during a competency evaluation.

Michael Keith Spell is charged with murdering Sidney High School teacher Sherry Arnold in 2012. His attorneys say Spell is not fit for trial because he is mentally disabled.

Psychiatrist Virginia Hill testified Tuesday that Spell showed a -- quote -- "relentless pursuit" of his own goals during his two-month stay at the hospital in Warm Springs. That included seeking access to video games and trying to get extra snacks.

Hill also says Spell emphasized in interviews that he could not read or write.

Prosecutors are seeking the death penalty. An alleged accomplice pleaded guilty under a deal with prosecutors.