Parents were frustrated and angry on Tuesday after a hoax about an armed gunman on the campus of Allesandro Elementary School in Silver Lake.
"They need to catch this clown," Melissa Gabriel, a mother with two daughters at the school, said. "The rooms are locked. They put them underneath their desks. Lights go off. They have to just listen to what the teachers tell them.
"She gets nervous, scared, stomach starts hurting," Gabriel said of one of her daughters. "The whole deal with the cops coming into the classroom."
Since the beginning of the school year Aug. 12, police have responded to at least three calls at the school from the same cellphone number, a line police are trying to track down, LAPD Capt. Jeff Bert said.
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It's a caller using a disconnected cellphone that is still able to make 911 calls.
The caller made a claim that two men, dressed in black and carrying rifles, had entered the school.
It's a pattern LA school police say they've been tracking for nearly a year.
"We still do a full-and-thorough search because, 'What if?'" Deputy Chief Jose Santome, of the Los Angeles Unified School District Police Department, said.
Police believe they've identified the culprit, but have yet to make an arrest, Santome said.
The culprit is linked to the call that threatened Maclay Middle School in Pacoima last week, police said.
It's part of what appears to be a rash of school threats in the area -- from LA to Orange County over the last week.
Threats like these can lead to felony charges, Santome said.
It also ties up police resources, Santome said.
"We could be doing other things," he said.
"It's ridiculous," Gabriel said. "Whoever keeps doing this needs to stop.
"This is my worry. Every day I come and drop them off and I just want to know that they're safe."