The samurai-sword-wielding Johns Hopkins student who killed an unarmed man outside his north Baltimore home last fall was cleared by prosecutors, who said yesterday the student was acting in self-defense and no charges will be filed.

The investigation of the Sept. 15, 2009 incident concluded that John Pontolillo “reasonably believed he was in danger of imminent death or serious bodily injury and was justified in striking Donald Rice,” according to the letter written by Baltimore City State’s Attorney Particia C. Jessamy to Major Terrence McLarney, of the Homicide Section.

Jessamy’s description of what took place that night differs in some  ways from the earlier account offered by police in September. Baltimore Police  Department spokesperson Anthony Guglielmi said Rice had chest lacerations and that his left hand was nearly severed.

Here’s how it was described in an Associated Press story.

“Rice’s left hand was nearly severed — Guglielmi described it as ‘hanging on by a thread’ — and he suffered a severe cut to the upper body. He died at the scene.”

Jessamy wrote that “Pontolillo swung one time as the intruder approached. The single blow resulted in Mr. Rice’s death.”