The school was put on lockdown in the morning until authorities announced they had detained the individual they were seeking. The 15-year-old student was not identified.
A similar lockdown happened at the school on Monday, after a student - also a 15-year-old - reportedly brought a loaded gun with a high-capacity magazine onto campus.
Police arrest Redondo Beach student for allegedly bringing loaded gun to school
On Tuesday, Redondo Beach police were notified at 9:23 a.m. about a student in possession of a gun on campus. The student ran away on foot and the school was locked down as police investigated. A school employee and two officers found and detained the student, a 15-year-old in 10th grade with possession of a loaded firearm.
Police say the weapon was not fired, no threat was made and no injuries were reported. The lockdown was lifted at 10:03 a.m.
The department notes there was already an additional presence of officers on campus due to Monday's incident. Officers are looking into whether the two incidents are related.
The consecutive lockdowns have left plenty shaken in the usually quiet beach community.
"It is very serious and a lot of kids are scared," said student London Brown. "A couple of my friends were crying. And it's not a joke and it's not something to be taken lightly."
Many parents scrambled to the school after being alerted that a student was brandishing a handgun.
"He called me up and said, 'Mom come get me.' And I'm like, alright," said school parent Georgia Praudisch. "Because I want to be safe and it's to be cautious. And the times we live in these days, it's just not the world I grew up in."
Students are shocked that something like this has happened in Redondo Beach and are offering some advice to their classmates.
"Don't bring your guns to school," said student George Ryan Dillon. "Keep them at home, please."
The school will be closed Wednesday because of the two incidents so that staff members can work to review safety measures on campus but will reopen Thursday.
Police are expected to use dogs to sweep the campus for weapons and explosives while it is closed. Exit and entry points will be restricted and additional officers will be on campus when it reopens.
Parents are being invited to an online meeting at 8:30 a.m. Wednesday to discuss the incidents and safety protocols.
"The two back-to-back incidents are something we would never have imagined," the Redondo Beach Unified School District said in a joint statement with police. "We are going to need to work together to solve the issue of access to guns."