It could not be confirmed what school the students attended, but the four confessed to the break-in, Pleasanton police Sgt. Kurt Schlehuber said.
"The suspects were identified because they were bragging about what they'd done to other students," Schlehuber said. "One of the other students that overheard the suspects bragging about it came forward and notified school administration."
He said school officials brought in one of the students, who confessed to being involved.
"He gave up everyone else," Schlehuber said. "The others were all cooperative and took responsibility for everything that took place."
The damage was not as serious as originally indicated. The district estimated the damage at $25,000.
According to the initial report at the scene, filed by Community Service Officer Teri Steiner, "an unknown suspect entered the secured library and smeared fecal matter on the floor near her front librarian desk, the light fixture above the desk and on her desk chair. There was a 'got homework' book marker with fecal matter stuck to her computer monitor."
That book marker came from a stack of the same book markers located near her desk.
Steiner's report said both the east and north library doors were secured.
"There were no signs of forced entry to the library doors or to the roof hatch. The roof hatch opens to a computer room near the library. The door to the computer room was found propped open using a computer," the report said. "There were no signs of forced entry to the computer room door."
The report notes the library does not have an alarm system or security cameras.
The juveniles also drew a penis on the librarian's desk calendar, according to the report.
Police declined to prosecute the four.
"It's basically juvenile mischief. The elements of vandalism weren't there," Schlehuber said at the time.
No expulsions were on the school board June 4 agenda, although a district official said at the time the four were not allowed back to school for the duration of the year.
After the last school board meeting, Superintendent Parvin Ahmadi said, "We're in the discipline process."
The students may have been spotted on their way to the break-in.
During the investigation, a witness told police she was gardening in her front yard and observed male juveniles on bikes inside the courtyard area of the school near the office. The school is secured with a gated fence but in the past, she said, she'd seen juveniles climb over the fence with their bikes.
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