Police said the 7-year-old was wounded during an after-school program and is expected to recover.
MOUNTAIN VIEW, CA — A 10-year-old boy was detained after police said he stabbed a 7-year-old girl at Bubb Elementary School during an after-school program on March 11, leaving the child with three shoulder wounds before fleeing the campus.
Authorities said the girl was treated at the scene and released to a parent, and school officials later told families that she is expected to be OK. The case has shaken a Silicon Valley school community because police said the boy did not attend Bubb Elementary and was not enrolled in the after-school program where the attack happened. Investigators have not publicly explained how the boy came onto campus, what led to the stabbing or what relationship, if any, the two children had.
According to Mountain View police, emergency dispatchers received reports at about 3:30 p.m. that a student in an after-school program had been stabbed in the school play area at Bubb Elementary, in the 500 block of Hans Avenue. Patrol officers responded and placed the school on lockdown while they secured the area. Officers then found the 7-year-old girl with three stab wounds to the shoulder. A kitchen knife that investigators believe was used in the attack was recovered at the scene. Fire department personnel treated the girl there rather than taking her to a hospital, and she was later released to a parent. Superintendent Jeff Baier told families in an email, as reported by local news outlets, that staff called police immediately after the attack and that the injured student was expected to recover.
Police said the boy had already run from the campus before officers arrived. During a neighborhood search, investigators reviewed residential surveillance video and a patrol officer recognized the child from earlier contacts with police, authorities said. A Los Altos Police Department K-9 unit then helped track the boy from the school to his residence. Officers coordinated with a guardian and detained him without incident, police said. The boy was later transferred to Pacific Clinics, which the city identified as Santa Clara County’s juvenile mental health services provider. Because both children are minors, officials have released only limited identifying details. Police have not said whether prosecutors will seek a juvenile court petition, whether the boy had been on campus before, or whether any adults may face questions about supervision or access to the knife.
The attack happened after regular school hours but while children were still on campus for a structured program, a detail that has become central to the community response. Bubb Elementary is a public K-5 school in the Mountain View Whisman School District on Hans Avenue in a residential part of the city. Neighbors told local television stations they were stunned by both the age of the suspect and the setting of the attack. Andrew Laffoon, a resident whose children previously attended the school, told KTVU the episode came “out of left field.” Other residents voiced disbelief that a child so young was accused of carrying out a knife attack at an elementary campus. The district said school and district staff moved quickly and that the immediate focus shifted from emergency response to emotional support for students and employees who saw or learned about what happened.
That support effort is likely to continue as the investigation moves forward. Mountain View police have described the case as an open investigation. No public charging document had been announced in the reporting available Friday, and juvenile proceedings, if they are filed, would generally be handled more privately than adult criminal cases. Officials also have not said whether the boy will remain in treatment, return to a guardian’s custody or undergo further psychological evaluation. The district told families that counselors and mental health staff were made available to students after the attack. The city’s public statement thanked Los Altos police for assistance with the K-9 search but did not announce any arrest affidavit, court hearing date or broader threat to the public. For now, key unanswered questions include motive, how the boy got the weapon, and why he was at the school.
The case has left parents, staff and neighbors trying to make sense of a violent episode involving children at an elementary school playground. In a statement quoted by local media, the school district said, “We’re very grateful the student is expected to be okay. The safety of our students is always our top priority.” The district added that staff acted quickly and police responded immediately. Mountain View Voice reported that some children in the after-school program witnessed the attack, adding another layer to the school’s recovery efforts. By late Friday, authorities were still withholding many details because of the ages of the children involved. What is clear is that the victim survived, the suspect was found within hours, and investigators are still piecing together why a 10-year-old boy who was not part of the campus community was there when the stabbing happened.
The investigation remained open Friday, with police and school officials expected to release more information only if juvenile court action or additional findings make that possible in the days ahead.
Author note: Last updated March 14, 2026.