The gun used by a 16-year-old who shot and killed three children and a teacher at Silver Rail Elementary School in Bend, Oregon, last week was a birthday gift from the shooter’s mom, sources told CBS News.

The Maverick 88 pump-action 12-gauge shotgun was purchased legally in August 2026 by Shauntai Nickerson, the mother of Griffin J. John II, and given to him for recreational use, the sources said.

In 2020, Nickerson told a local television station that her son, who was 10 years old at the time, had special needs and was struggling with remote learning during the pandemic. She told KTVZ, “It’ll be great for my son to get back in there and get the help that he needs with the skilled teachers that he needs to get it from.”  

The shooter initially fired at a passing pickup truck, whose driver made the initial 911 call, before forcing his way into the school by shooting through the glass panes of a set of double doors, police said last week. He then went into the first classroom to the left of those doors, where he killed all four victims and wounded two others.

The children killed in the shooting were ages 5, 8 and 11, police said. The teacher who was killed was identified as 25-year-old Megan Lambert. The 5-year-old victim was identified by police and his family as Rhoam Summer. The families of the two other children have not made their names public, Bend police said. 

Two wounded victims are a 7-year-old girl and a 54-year-old teacher.

Police said Monday there were a total of nine people — four adults and five children — in the classroom at the time. 

The shooter was shot and killed by a bystander, 36-year-old Kaylub Giamanco, who saw the first shooting with the pickup truck and followed the shooter into the school. Giamanco is a Bend resident with two daughters who attend Silver Rail Elementary School.

The suspect was a former student of Silver Rail Elementary, police said. No motive for the attack has been provided. 

The Bend Police Department said Monday it expected to finish collecting evidence at the school by the end of the day, and would then turn the building back over to the school district. 

Law enforcement sources previously told CBS News that investigators are combing through the computer, phone, social media, search history and other online activity of the attacker.