The gun was found Friday night at Veterans Memorial Stadium during Buchanan High School's season-opening football game, where thousands of students, parents and community members had gathered.
"He put thousands of kids' lives at stake last night," said Clovis parent Tom Byas.
Byas said his son discovered the firearm inside a bathroom stall and acted quickly to prevent anyone else from accessing it.
"As he guarded the stall, he had his friends run out and notify the police to come in there immediately," Byas said.
The discovery shocked many attendees and raised concerns about what could have happened had the weapon been found by someone else.
"Had there been a child who was disgruntled with the first week of school, having issues, not there mentally..." Byas said. "Being a cop, you've got what, 15 rounds in your gun? He could have killed 15 children last night. So I'm very concerned about this."
The following day, Alta Sierra Middle School addressed the incident in a statement, saying, "We recognize that the outcome could have been heartbreakingly different..." The statement also said the district is "already revisiting practices allowing off-duty officers to maintain possession of their service weapons at all times."
Neither the school nor Clovis Unified identified the law enforcement agency that employs the officer. The district also did not provide the information when asked.
Byas argued that the public deserves greater transparency, saying the situation would have been different if a law enforcement official had not left the gun behind.
"They would have inspected the serial number. They would have found out who you were. They would have been at your house arresting you and confiscating every one of your weapons at that point in time, and put you in jail last night," he said.
The incident occurred the same night a 17-year-old was fatally shot at a separate high school football game in Bakersfield. Authorities later arrested a 15-year-old in connection with that shooting.
Byas said the timing heightened concerns about the potential consequences of an unattended firearm at a crowded school event.
"Having an officer of the law who's supposed to be upholding the law, and we all got to look up to, being so irresponsible. He needs to go," he said.
Clovis Unified said its police department is working with the officer's agency to address the incident. It remains unclear what disciplinary action, if any, the officer could face.
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