At 9:59 a.m. Wednesday, someone contacted police to report a male tucking a handgun into his clothing and walking on to the campus at 1776 Educational Park Drive.
In response, the school went into lockdown mode for about three and a half hours while police surrounded the campus and conducted searches for the suspect, according to San Jose police Sgt. Jason Dwyer.
By the time the lockdown had lifted, police had still not found the gun.
But on Thursday, students at Independence High came forward and admitted to school officials that they knew the student who had brought the Airsoft pistol onto school campus.
The 15-year old student was then called before school officials and admitted to bringing the replica firearm onto campus the day before.
Police then went to the student's home to retrieve the gun, cited the student and released him to his parents. The student, whose name is not being released because he is a juvenile, was also suspended from school, police said.
According to Dwyer, even though the gun is only a "replica firearm" that shoots pellets, brandishing and bringing such an item onto a school campus is still a crime.
Dwyer noted that the concerned citizen had been right to report the crime.
"He was there with the gun, we just didn't find it that day," he said.
Dwyer added that officers had conducted the search by contacting teachers with a description of the suspect, then gathering about 20 students matching the description for a "pat search."
He said the school is simply too massive to search classroom by classroom.
When asked how much the lockdown cost the city, Dwyer said, "30 officers for four hours ... you do the math."