This morning, the Wash Post has a longer analysis of the massacres at Virginia Tech and NIU, and the security response on each campus. Weirdly, the killers used the same Internet arms dealer:

On the same day he bought those firearms, Kazmierczak went online and purchased two Glock 33-round magazines that would allow his pistol to carry many more than the standard number of bullets. He bought the magazines from the same Internet company that had sold Seung Hui Cho, the Virginia Tech killer, a .22-caliber handgun.
“I felt just shocked, like I had been hit with a truck,” said Eric Thompson, president of Tgscom, a licensed firearms dealer in Green Bay, Wis., which operates the Web site. “There’s over 90,000 licensed dealers in the U.S., and what are the chances that my company is involved with two mass murders inside of a year? I’m just dumbfounded.”