A mistrial was declared Friday in the case of a former Harvard graduate student charged with stabbing a teenager to death during a fight.
The jury was unable to reach a verdict after 10 days of deliberations.
This was the second trial for Alexander Pring-Wilson, 29, who was accused in the death of 18-year-old Michael Colono. Pring-Wilson said he acted in self-defense after he was attacked by Colono and his cousin, Samuel Rodriguez, outside a Cambridge pizza parlor as he walked home from a bar on April 12, 2003.
The case attracted widespread media attention because of long-standing tensions between Ivy Leaguers and working-class Cambridge residents.
Pring-Wilson, the son of Colorado lawyers, was studying for his master's degree in Russian and Eurasian studies at Harvard. Colono, a high school dropout, had fathered a child at 15. He had earned his equivalency diploma and was working as a cook at a Boston hotel when he was killed.
Pring-Wilson will remain free on bail.
Pring-Wilson was convicted of manslaughter in 2004, but won a new trial eight months later when the state's highest court ruled in another case that juries should be allowed to consider a victim's violent history if it is relevant to a claim of self-defense.
During the second trial, jurors were given details about Colono's criminal record, including a 2001 episode in which he threw money in the face of a cashier at a pizza restaurant, then kicked in the front door and shattered the glass.
Pring-Wilson testified Colono and Rodriguez both pounded him relentlessly in the head, and he pulled out his folding knife because he was afraid they would kill him. But Rodriguez told the jury that Pring-Wilson attacked Colono after Colono made a derogatory remark about Pring-Wilson's apparent drunkenness.