SAN JOSE, Calif. (KTVU) - San Jose Police are trying to determine who left a sophisticated bomb on the campus of Oak Grove High School Tuesday.
Apprehensive students returned to Oak Grove High School on Thursday knowing two things for certain: The bomb found on campus was real, and the person responsible for putting it there is still at large.
Student Matthew Pacleb said, "It's been a lot of worries actually. Some nonchalant. Some sad. It's just shocking."
On Tuesday, students were first told to shelter in place, then evacuated to a nearby park.
The bomb had been discovered by a staff member near the student parking lot and then brought in to the administration building.
San Jose Police Chief Eddie Garcia said "We're very concerned that this was left where it was left, in one of our most vulnerable areas. And we're doing everything possible to identify the individual responsible for it."
To do that, San Jose Police said they're investigating the bomb itself, looking for clues. They're also checking nearby surveillance cameras, and asking families to report any suspicious behavior.
Chief Garcia said, "It's distasteful to talk about. It's uncomfortable to talk about, but we have to. We have to be vigilant in today's era. And unfortunately, that's what we have to do. And so if people see something they need to say something."
At Oak Grove, teachers were trained Wednesday on how to spot students in distress. The school held a separate parent meeting too. And then on Thursday, there was an added police presence to reassure students.
Glenn Vander Zee Associate Superintendent of the East Side Union School District said, "This morning police did an additional sweep before school began. There's a presence within the neighborhood. And within the site we have additional social workers in place."
Still, students say they'll be looking over their shoulders, at least until the bomb maker is caught.
Pacleb said, "Just the abundance of help the school is providing and just my friends and support, I've been doing fine. But we always have to be careful with our surroundings."
The bomb is being examined at the crime lab, though it will likely be sent to the FBI's facility in Virginia for further testing. Anyone with information on this case is asked to call the San Jose Police Assault Unit at 408-464-8379.