BLACKSBURG, Va. - More than a week after Seung-Hui Cho killed 32 people during a rampage at Virginia Tech, investigators have yet to find a motive, despite examining his computers, e-mail and cell-phone records.

Authorities have found no evidence that could begin to explain the massacre that ended when Cho took his own life, State Police Superintendent Col. W. Steven Flaherty said in an interview last night.

Authorities also have failed to find a link between the 23-year-old loner and his victims.

Flaherty plans to update reporters and the Virginia Tech community at a news conference this afternoon on what authorities have uncovered about Cho's rampage.

It could be months before police finish their work, and Flaherty said investigators would keep looking for any motive and a connection between Cho and the victims until all leads had been exhausted.

Flaherty said investigators also had been unable to answer one of the investigation's most vexing questions: Why the rampage began at the West Ambler Johnston dorm, and why freshman Emily Hilscher, 18, was the first victim.

He said police had searched Hilscher's e-mail and phone records but came up empty. "We can't make a link at this point," Flaherty said.

Cho also killed resident adviser Ryan Clark, 22, a senior, at the dorm before moving on to Norris Hall. Authorities also have been unable to determine why Cho picked that building, which is home primarily to engineering offices, to continue his attack.

Also yesterday, Virginia Gov. Timothy M. Kaine said he might be able to close the 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 conduct background checks on prospective gun buyers.

A special justice ordered outpatient psychiatric counseling for Cho 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 might be able to tighten that reporting requirement by issuing an executive order.

Visit Virginia Tech's Web site to see school tributes to those killed via EndText