California High School has received five threats this school year, according to the district. The FBI is now a part of the investigation.
San Ramon Police tell ABC7 News they're actively pursuing leads, but don't know who is responsible.
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"We don't have anything at this point to substantiate a credible threat," Corporal Mike Pistello said. "But, we also don't know. We can't say for certain either."
Wednesday's threat was the third the school has received since last Tuesday. One threat was on the football field, and the other two were found in bathrooms.
The most recent threat included a racial slur and called out Black students. Nena Hicks, a California High School parent, is shocked.
RELATED: Message threatens May 9 school shooting at California High School in San Ramon
"Everybody are equal over here," Hicks said.
Unlike a few other parents ABC7 News talked to Wednesday night, Hicks didn't want her daughter to stay home.
"I know my kid is safe," Hicks said.
"When I heard that the San Ramon Police Department was going to be down here, that made me feel much more comfortable about bringing Avery down, so he could take his AP test," Chris Elkin, a California High School parent, said.
RELATED: Police increase patrols at California High in San Ramon after threatening message found
Elkin said his wife is a teacher with the San Ramon school district. He said the district is delaying the AP, or advanced placement test, for some students.
California High School is also providing resources for students who may be shaken up.
"The plan is to ensure safety and make sure things go as smoothly as possible," Corporal Pistello said.
The San Ramon Police Department will remain at the school throughout Thursday.
Since last Tuesday, California High has experienced 3 threats. Most recent was a #schoolshooting threat. FBI is on campus today. Police say they’re investigating leads @abc7newsbayarea pic.twitter.com/jhtH2gE1Jf— Jobina Fortson (@JobinaFortson) May 9, 2019
Some parents are keeping their children home from California High today. A #schoolshooting threat was found in a bathroom. It included a racial slur and called out black students. Principal says there will be “considerable police presence” and extra admins today @abc7newsbayarea pic.twitter.com/smBPEVnTm3— Jobina Fortson (@JobinaFortson) May 9, 2019