Hours earlier, someone had broken into John Pontolillo's house and taken two laptops and a video-game console. Now it was past midnight, and he heard noises coming from the garage out back.
The Johns Hopkins University undergraduate didn't run. He didn't call the police. He grabbed his samurai sword.
With the 3- to 5-foot-long, razor-sharp weapon in hand, police say, Pontolillo crept toward the noise. He noticed a side door in the garage had been pried open. When a man inside lunged at him, police say, the confrontation was fatal.
"He was backed up against a corner and either out of fear or out of panic, he just struck the sword with force," said Baltimore Police spokesman Anthony Guglielmi. "It was probably with fear for his life."
Pontolillo, who rents the house in the 300 block of E. University Parkway in the Oakenshawe neighborhood, struck the intruder no more than twice, police say, nearly severing his left hand and inflicting what police termed a "spear laceration."
The intruder, Donald D. Rice of Baltimore, a 49-year-old repeat offender who had been released from jail only Saturday, died at the bloody scene.