BLACKSBURG, Va. -- "He never said a word the whole time. I've never seen a straighter face."
That is how Trey Perkins, a senior at Virginia Tech, recalled the gunman who burst into his German class here on Monday, pointed a handgun at each student and pulled the trigger.
In the end, Perkins, who crouched behind desks in the back of the classroom, escaped uninjured.
But he was one of the few. The classroom on the second floor of Norris Hall appears to be where the gunman, a 23-year-old student identified as Seung-Hui Cho, exacted his greatest toll -- killing as many as a dozen people.
It was a scene of terror and panic inside Room 207, with students trying to escape through windows or cowering under desks as the gunman fired, reloaded, and then fired again.
At one point, the gunman left inexplicably, only to return, with students wedging themselves against the door to block his entry. "The guy tried to come back in, and we were able to hold him off," Perkins said.
Before the initial attack, the class of roughly 20 students had been gathered for about an hour as the professor, Christopher Bishop, delivered a lesson on the rudiments of German, witnesses said.
At that point, there was nothing out of the ordinary, except for when someone opened the door and began peeking into the room. The class assumed that it was a lost student looking for a classroom.
But about 10 minutes later, the door swung open, and the shooter entered and took aim at Bishop, a popular 35-year-old professor known for riding his bicycle around the campus.
Cho then turned on the horrified students, who hit the floor and pushed over desks to shield themselves, starting with those seated in the front rows of the classroom, the witnesses said.
Derek O'Dell, a 20-year-old biology student who was in the classroom, told The Roanoke Times: "He was very quick in reloading, so he looked like he'd been trained."
Then, for reasons that are unclear, Cho suddenly stopped firing and left the room, as the professor and students lay bleeding on the floor.
A few minutes later, the gunman tried to force his way back inside the classroom . Cho opened the door a crack, but the students pushed back hard enough to prevent him from entering.
Looking back, Perkins said he could not get over how methodical Cho had been.
"He was just disgusting, he just had no facial expression, showed no signs of emotion or anything," he said.