The lawyers for Alexander Pring-Wilson attempted to humanize the 26-year-old defendant yesterday by calling a slew of character witnesses who referred to him by his nickname of “Sander” and testified that the accused murderer has what the defense repeatedly referred to as “a reputation for peacefulness.”

Pring-Wilson, the former Harvard graduate student who admitted to stabbing Cambridge’s Michael D. Colono, 18, outside Pizza Ring on Western Avenue in April 2003, claims that he acted in self-defense.

Philip Najm, who played rugby with Pring-Wilson at Colorado College, testified yesterday that he used to speak with his friends about Pring-Wilson’s reputation for pacifism.

“He was a peaceful player. He was never an aggressive player,” Najm said on direct examination.

But on cross-examination, Assistant District Attorney Adrienne Lynch challenged Najm to provide specifics of when he had talked about Pring-Wilson’s pacificism.

“Regarding your friendship with Mr. Pring-Wilson,” Lynch asked, “You would do anything for him, wouldn’t you?”

Najm responded that he would do anything for Pring-Wilson—”anything under the law.”

The defense called Jonathon S. Lee, a philosophy professor at Colorado College who taught the defendant in three courses. Lee affirmed Pring-Wilson’s peaceable nature.

“Sander was known as someone who was very sweet and good to work with in the classroom,” Lee said. “He wasn’t confrontational.”

But Lynch questioned whether acting peacefully in a classroom setting was even noteworthy.

“In your experience at the university, do fights usually break out among students over the classics?” Lynch asked sarcastically, winning chuckles from the audience.

Professor of the Classics at Colorado College Marcia Dobson had a ready-made answer when Lynch asked her the same question on cross-examination.

“Students get rambunctious when they study Ancient Greece,” Dobson said. “Sander always put out the fire.” Among the defense’s witnesses yesterday was Pring-Wilson’s girlfriend, Janice N. Olmstead. Pring-Wilson called her four times in the hours after the stabbing, leaving two messages on her voice mail.

“He sounded confused, floaty. I’ve never heard him sound like that,” Olmstead said.

Though Olmstead had told police that Pring-Wilson sounded drunk that night, according to the prosecution, Olmstead said she did not recall telling it to the police.

The defense also called Melissa Leslie, an employee at Chesapeake Knife and Tool, who testified that the $129 pocketknife Pring-Wilson used to stab Colono was a “utility knife, a rescue knife,”—one she carries around herself.

In other developments in the case, the defense asked for a directed verdict on Thursday, claiming the prosecution had not met its burden of proof.

The motion was turned down by Justice Regina Quinlan.

Press Secretary for the District Attorney Emily J. LaGrassa said such a motion is common in first-degree murder cases because it allows the defense to appeal a guilty verdict.

Pring-Wilson is expected to testify this week, although exactly when is a closely guarded secret.

—Staff writer May Habib contributed to reporting of this story.

—Staff writer Robin M. Peguero can be reached at peguero@fas.harvard.edu.