Memphis student planned ahead for stabbing death of principal (VIDEO)

A 17-year old Memphis Junior Academy student chose Wednesday to stab his principal to death because he knew he’d be alone in a classroom with her, according to a police affidavit.

Eduardo Marmolejo told police Wednesday that he had planned to kill his principal since May, saying he didn’t like Suzette York and "she made him angry," the Memphis Commercial Appeal reports.

Marmolejo stabbed York, 49, multiple times about 11 a.m., leaving her in a pool of blood, police reportedly said.

Officers responded to a call at 11:15 a.m., CNN reports. "Upon arrival on the scene, officers located a deceased female inside of a classroom," Sgt. Alyssa Macon-Moore reportedly said.

Marmolejo is being held at a Juvenile detention center on a charge of first-degree murder.

A prayer vigil was held late Wednesday outside the small East Memphis private school, which is affiliated with the Seventh-day Adventist Church.

A former student of York, Kristen Bridges, described her as an exemplary biology and math teacher.

"It's tragic all the way around," Mayor A.C. Wharton Jr. said, CNN reports.

The police affidavit reportedly read:

"Eduardo Marmolejo admitted that he had stabbed his teacher Suzette York multiple times because he did not like her and she made him angry. [He] said that he had been planning to kill Mrs. York since May 2011 when he learned he would be returning to the Memphis Junior Academy. [He] said that he planned to kill Mrs. York [Wednesday] because he knew she would be alone in the classroom with him."