"We are at a point in time when we are closing out our on-scene investigation just now and now we move on to the task of reviewing and interviewing and reinterviewing and combing through the mounds of evidence we've collected," Col. Steven Flaherty, head of the state police, said Thursday morning.
But just hours after Flaherty said evidence collection was wrapping up, Virginia Tech university police sought and received search warrants allowing them to recover a laptop computer and cell phone belonging to Emily Hilscher, a resident of Ambler Johnston Hall and presumed to be one of the first two victims in Cho's killing spree -- apparently searching for any link between killer and victim.
"The computer would be one way the suspect could have communicated with the victim," Virginia Tech Det. Stephenie Henley wrote in search warrant affidavit obtained by ABC News. "It is highly likely that information would still be on the computer."
The warrant for the cell phone also suggested that Hilscher may have received some type of communication from Cho by phone.
That type of behavior would be consistent with incidents involving Cho in November and December of 2005 that lead female students to contact police.
One young woman complained that Cho, then 21, was stalking her, but she declined to press legal charges against him. Police interviewed Cho for the first time and referred the case to the school's internal disciplinary board.
A second woman student, less than two weeks later, told authorities she received disturbing instant messages from Cho, and asked police to make sure there was "no further contact" from him.
Evidence of Cho's planning became abundantly clear when NBC received a package the killer sent from the Blacksburg post office after killing two people in a campus dormitory and before opening fire in the Norris Hall academic building, killing 30.
NBC News -- having been widely criticized for airing extended portions of the videos Cho mailed to the network -- posted more material from his package on its Web site, MSNBC.com. Cho had assembled many of the pictures he sent in a 23-page computer document, adding captions.
"Oh the happiness I could have had mingling among you hedonists, being counted as one of you, only if you didn't --- the living --- out of me," reads one line above a picture of a smiling Cho.
On another page is this line: "You wanna rape us John Mark Karrs? You wanna rape us Debra LaFaves? --- you."
John Mark Karr was the man who claimed last year that he had raped and murdered 6-year-old Jon Benet Ramsey in 1996, but was released after authorities concluded his confession was false. Debra LaFave was a Florida teacher who pleaded guilty to having sex with a 14-year-old student.
NBC said the computer file from Cho had last been modified at 7:24 a.m. on Monday, just minutes after the first shootings. The network said it blocked out Cho's expletives.