We've come to Centreville in northern Virginia to see what clues we can find that might unlock the mystery of why 23-year-old Cho Seung-Hui would turn killer, ruthlessly mowing down his fellow students and teachers in cold blood. I half expect to find something abnormal in his hometown but I am struck by its absolute normality.
At first glance, Centreville looks like a newly minted American suburb, with clusters of brick townhouses nestled in tree-lined cul-de-sacs and small shopping malls designed with faux-early American touches. Look closer and you see signs of the new American melting pot.
We stop at the Grand Mart, an Asian food store where the signs, some of the food and even the music is Korean. The place is huge and spotless. Koreans, Indians, Chinese -- they're all here. A well-dressed engineer, Rosemary Hsu, an immigrant from China, tells me there is pressure here on young people to succeed. It's not just the well-known striving of Asian families to get a good education for their children, she tells me, it's something any family here feels.
We drive to Westfield High School where Cho, a resident alien from South Korea, graduated in 2003. A school official emerges and lets us shoot pictures of the yearbook. On one page she blots out the faces of the other students with yellow "stick-it" notes, leaving the small photo of Cho looking completely unremarkable.
The yearbook is from 2002, she notes, when Cho was a junior. He never appeared in his senior book. No clubs, no activities. A loner.
As we finish shooting video of the yearbook, the police herd us across the highway away from the high school. The students are being let out for the day and they don't want us talking to them on school property. Several police cars are parked near the entrance.
As the kids swarm out the doors, they board a row of yellow school buses. We wave and call to them, hoping some might talk with us, maybe someone knew Cho or his family. A few look our way, but most climb aboard the buses and begin to drive away. From a distance, they look so vulnerable -- young people on their way home to parents who love them and now, perhaps, think more anxiously of whether they will come home safely.
We set off for Cho's home. It is a small but pleasantly bland townhouse painted beige. The FBI, state police and local police searched it Monday night. Cho's parents, Cho Sung-tae, 61, and his mother, Cho Hyang-ai, 51, both employees in a dry cleaning business, have left for an undisclosed location and the street is surrounded by TV live trucks and police cars.
A mail carrier who delivered mail to their house describes the parents as "super nice." Cho had a sister who graduated from Princeton University.
We get word that one of Cho's victims lived in Centreville, and as we drive to her house, we realize she lived just two minutes away by car. Reema Samaha, a student at Virginia Tech, was among those killed at Norris Hall. She was a talented dancer and her parents had watched her perform over the weekend. Now, friends gather outside their house, protectively huddling near the front door.
Another sad twist of fate: Samaha had graduated from the same high school as Cho.
In a Virginia state police photo, Cho stares straight ahead, peering through wire-rimmed glasses with dull, expressionless eyes. He reportedly rarely talked with people, even with his college roommates. His only expression of emotion came in macabre, violent plays he wrote for an English class. "Like something out of a nightmare," a fellow student called them.
Then something happened. Whatever was boiling inside Cho exploded with lethal fury. In the ultimate act of hatred, he destroyed even himself, leaving others to decipher the ultimate question: Why?
-- By Jill Dougherty, U.S. Affairs Editor for CNN International