BALTIMORE - Baltimore homicide detectives don't believe a Johns Hopkins University student had "the intent to kill" when he used a samurai sword to confront an intruder behind his home, a police spokesman said Thursday.

John Pontolillo, 20, a junior chemistry major from New Jersey, killed the man with a single blow early Tuesday after police said the suspected burglar lunged at him.

Pontolillo has not been charged in the death of Donald D. Rice, 49, who had a long rap sheet of burglary arrests and was released from jail just two days before the altercation. Prosecutors will determine whether charges are appropriate after consulting with police, a process that could take weeks.

"We do not believe he went down there with the intent to kill somebody," police spokesman Anthony Guglielmi said of Pontolillo. "We're looking to see if he was the aggressor, and so far the evidence doesn't suggest that."

When Pontolillo saw Rice, he raised the sword and yelled for his roommates to call police, Guglielmi said. Rice lunged at the student, who backed up against a wall. At that point, Pontolillo struck Rice once with the sword, nearly severing Rice's left hand and causing a severe wound to his upper body. Rice died at the scene.

Guglielmi said Thursday that when the student found Rice, he was was hiding in the small, fenced courtyard between the back porch and the detached garage behind Pontolillo's off-campus home. Police had initially said Rice was hiding inside the garage.

Police also revealed that Pontolillo and his three roommates, all Hopkins students, had been warned by a city officer and a campus security officer late Monday about a suspicious person in the neighbourhood just east of campus.

At that point, the students told the officers that Pontolillo's XBox video game console and two laptop computers had been stolen from their home earlier that night. Police investigated and found no signs of forced entry, according to police reports about the thefts.

After the officers left, Pontolillo retrieved the sword and decided to perform a more thorough search, including the garage and his car, Guglielmi said. The officers heard the screams during the encounter with Rice and rushed back to the scene, he said.

Pontolillo has not returned calls seeking comment. A man who answered the phone at the home of John A. Pontolillo of Belmar, New Jersey, said he had no comment.

Rice's sister, Peggy Rice, told WJZ-TV in Baltimore Wednesday that her brother did not deserve to die and that the student should be charged.