Computer files, cell phone records and e-mails have yielded no evidence about what triggered Seung-Hui Cho's massacre at Virginia Tech last week or whether he singled out any of his 32 victims.

In an interview Tuesday with The Associated Press, State Police Superintendent Col. W. Steven Flaherty said authorities have found no evidence that could begin to explain the massacre that ended when Cho took his own life.

Authorities also have no link between the 23-year-old loner and his victims.

"We certainly don't have any one motive that we are pursuing at this particular time, or that we have been able to pull together and formulate," Flaherty said. "It's frustrating because it's so personal, because we see the families and see the communities suffering, and we see they want answers."

Flaherty spoke to the AP after spending the day in meetings with investigators to prepare for a Wednesday afternoon news conference about what authorities have uncovered.

Flaherty, who is overseeing the investigative team looking at the shootings, said police also have been unable to answer one of the case's most vexing questions: Why the spree began at the West Ambler Johnston dorm, and why 18-year-old freshman Emily Hilscher was the first victim.

Police have searched Hilscher's e-mails and phone records looking for a link. While Flaherty would not discuss exactly what police found, he said neither Cho's nor Hilscher's records have revealed a connection.

Flaherty cautioned that it could be months before the case is closed. The investigation will begin slowing down as authorities examine evidence, he said.

"If we get to a point when we reach the end of this investigation, whenever it is, and we don't have those answers that they need, it's really difficult to sit down and say I just don't know."

Flaherty said there was also no link to 22-year-old senior Ryan Clark, who was also killed at the dorm. Nor do investigators know why Cho, an English major, selected Norris Hall — a building that is home primarily to engineering offices — to culminate his attack. Cho killed 30 people there before taking his own life.

Frustrating their effort, Flaherty said, is the fact that Cho revealed himself to so few people. Even family members have said they rarely heard him speak.

"I guess the thing that is most startling to me, I say startling, surprising, is a young man who's 23 years old, that's been here for a while, that seemed to not know anybody," he said.

Gov. Timothy M. Kaine said Tuesday he may be able to close a loophole that allowed Cho to buy guns. Federal law bars the sale of guns to people who have been judged mentally defective. But it is up to states to report their legal proceedings to the federal government for inclusion in the database used to do background checks on prospective gun buyers.

In Cho's case, a special justice ordered outpatient psychiatric counseling for him in 2005 after determining he was a danger to himself. But because Cho was never committed to a mental hospital, that order was never entered in the database.

Kaine, a Democrat, said in a radio interview that he may be able to tighten that reporting requirement by issuing an executive order.

The governor met with Korean-American leaders to assure them that Virginians do not hold people of Korean descent responsible for the tragedy. Cho was a South Korean immigrant who came to the U.S. at about age 8 and was raised in suburban Washington.

"I can assure you that no one in Virginia — no one in Virginia — views the Korean community as culpable in this incident in the least degree," Kaine said.

He said state officials will watch for any reprisals against Korean Americans but that none have been reported.

The Virginia Korean leaders asked Kaine to boost mental-health funding for immigrants and their families.