The attack killed three children, ages 5, 8 and 11, and a 25-year-old teacher. Two other people were seriously injured. Police said Giamanco’s intervention likely prevented further deaths at the school, which has more than 400 students.

Giamanco said he was four blocks from home when he saw the teenager shoot at a pickup truck and a woman near the school grounds. When the teen climbed over the school fence, Giamanco retrieved a handgun from his truck and called 911.

“I’m sorry, I have to go in. People are going to die,” he recalled telling the dispatcher before entering the grounds.

Giamanco said he followed the shooter toward a side entrance, then crawled through a broken window after hearing gunfire and children pleading. He saw a teacher struggling with the teen inside a special education classroom and fired. The teacher fled; Giamanco said he then shot the teenager again when he saw him reaching for his weapon. He put his gun down and raised his hands when police arrived.

Afterward, Giamanco called his wife and told her he would not be coming home for the lunch they had planned. He also called his mother, who urged him to calm down and told him he had done the right thing. Giamanco said his first response was that he had not saved everyone.

In the days after the shooting, he said, he has struggled to sleep and relives the sounds and faces from the school. He has also wondered whether he could have acted sooner. He expressed gratitude to the teacher who grappled with the shooter, saying her actions gave him an opportunity to intervene, and said he wants to apologize to the families of those who died.

The shooting has brought intense attention to Giamanco and his family, including calls from media and political advocacy groups. He said he is an independent and does not want his actions turned into a political argument. Deschutes County reported a rise in applications for concealed handgun licenses following the attack.

Giamanco grew up in Bend as the oldest of seven siblings and later trained as a carpenter. He said military veterans he met through a construction job taught him firearms skills. He described the gun he carried in his truck as one he rarely used.

He is considering organizing a motocross race to raise money for school safety improvements, such as stronger door locks and reinforced glass. He also supports placing school resource officers in every school. His own daughters, who attended Silver Rail, have not returned to school since the shooting, and the family has stayed away from home because it is near the campus.

Giamanco said his family is trying to cope through ordinary routines, including meals and board games, while he reassures his daughters that he loves them and will protect them. He said he does not know whether he will return to carpentry, but feels compelled to use the public attention to make a difference.