SPARKS, Nev.The student who on a Nevada middle school campus was 12 years old.
District police say the boy brought the weapon used in the Monday morning spree from home. They are still working to determine how he obtained the 9mm semi-automatic Ruger handgun.
Authorities say they are withholding the Sparks Middle School student's name out of respect for his family. But School District Police Chief Mike Mieras released the seventh-grader's age at a news conference Tuesday.
Police say the boy's parents are cooperating with them and could face charges in the case.
Also at the new conference, police lauded the actions of 45-year-old math teacher and former Marine Michael Landsberry. They say he tried to stop the rampage before he was fatally shot in the chest.
At 7:15 a.m. on Monday, the student shot a fellow student in the shoulder, walked toward Landsberry, shot him in the chest, then walked south and shot a second fellow student in the stomach before finally turning the gun on himself.
"I heard a loud bang, like really loud, it made my ears ring," 13-year-old Michael Anduja told CBS News' John Blackstone. He said he turned and saw the shooter aiming a gun at students.
"There were a couple kids trapped in a doorway. They had nowhere to go. Mr. Landsberry stepped in front of them and saved them," Michael said. "He (the shooter) was aiming at them and Mr. Landsberry stood in front of them and the kid shot him."
"When I found out he was dead, it was pretty heartbreaking," Michael said of Landsberry. "I can't imagine school without him."
The popular math teacher was not the only hero, Michael said. He said some students who were out of the line of fire ran back to help classmates who were too frozen with fear to run.
At least one witness has.
"He pointed to us and he said, 'You ruined my life and now I'm going to ruin yours,'" said Alfrancis de Vera, a student at Sparks Middle School.
Classes are canceled for the rest of this week at Sparks Middle School, reports CBS affiliate KTVN in Reno. Neighboring Agnes Risley Elementary canceled classes for today as well; classes will resume Wednesday.
A candlelight vigil is scheduled for Wednesday at 7 p.m. in front of Sparks Middle School. The Patriot Guard and various veteran groups will participate in an honor guard.
The Sparks Nazarene Church will hold a community prayer on Thursday at 6:30 p.m.
The Community Foundation of Western Nevada has set up a fund to help victims' families. You can donate to the "Compassion Fund" at 775-333-5499 or go to www.nevadafund.org. Police warned the community to be aware of possible scams, and urged people to use the Nevada Fund link.