At a pretrial hearing yesterday, several witnesses testified on the mental and physical health of a Harvard graduate student around the time of his arrest, after he allegedly killed a local teenager last April.

The hearing will continue today, when Judge Charles M. Grabau may decide whether to permit alleged lies Alexander Pring-Wilson told police on the night of his arrest as evidence.

Pring-Wilson, a student at Harvard’s Davis Center for Russian and Eurasian Studies at the time of his arrest, is charged with stabbing 18-year-old Michael Colono to death on April 12, 2003 after an early morning altercation outside of Pizza Ring, a local pizza parlor on Western Avenue.

Pring-Wilson’s attorney Jeffrey A. Denner said his client acted in self-defense.

On Feb. 23, Denner filed a motion in Middlesex Superior Court claiming Pring-Wilson was suffering from a concussion and post-traumatic stress disorder at the time of his arrest, and therefore the statements his client made to police and friends “were not knowing, intelligent or voluntary,” which they must be in order to be admitted as evidence.

The motion argued that Pring-Wilson was unfit to recount events accurately, and his statements from that night should therefore not be presented at his trial, scheduled for June 3.

In her questioning yesterday, Assistant District Attorney Adrienne Lynch tried to convince Judge Grabau, who will be ruling on Denner’s motion, that Pring-Wilson’s ability to make accurate statements the night of his arrest was intact.

Before the hearing began yesterday, Lynch filed the prosecution’s written response to Denner’s motion.

Lynch called 11 witnesses yesterday—including police, fire and medical personnel. She asked about Pring-Wilson’s behavior and claims of head pain in the day and a half after his arrest.

Lynch’s first witness was Christopher Nellis, the state police dispatcher who answered Pring-Wilson’s cellular 911 call at around 1:50 a.m. on the night of the stabbing.

According to a tape recording of the 911 call, which was played in court yesterday, Pring-Wilson—contrary to the argument he acted in self-defense—told dispatchers he had witnessed a stabbing.

Nellis said when he called Pring-Wilson back to confirm the 911 call, Pring-Wilson only responded, “911 is a great thing.”

Nellis routed the call to Cambridge 911 dispatcher Michael Ferraro, another witness yesterday, who said that Pring-Wilson told him he denied seeing the stabbing.

Cambridge Police Department (CPD) officer Donald Mahoney, who responded to the 911 call, said that Pring-Wilson didn’t appear to be incapacitated.

“He said he just observed a stabbing and an individual had run off,” Mahoney said yesterday at the hearing.