A 17-year-old student charged with first-degree murder in the slaying of a Christian school principal has been detained without bond and ordered to undergo a mental evaluation.

Eduardo Marmolejo (mar-moh-LEH'-ho) is charged with killing 49-year-old Suzette York on Wednesday at Memphis Junior Academy, a Seventh-day Adventist school of about 100 students.

He had an initial appearance in Juvenile Court on Thursday afternoon.

Memphis Police say Marmolejo told investigators he planned to stab the principal on the third day of classes, when he knew he'd be alone with her in a classroom. Marmolejo told police he wanted to kill York because he did not like her and she had made him angry.

State law allows police to release the names of juveniles charged with first-degree murder.