Law enforcement and school officials have defended 21 months of secrecy around the murder investigation of a Panorama High School student at the hands of MS-13 — one part of a grisly rampage that has generated national headlines and left at least 10 people dead.

They said there was no need to alert teachers, parents and students because other students were never in danger, the gang had little presence on campus, and no acts of gang violence affected the campus itself.

But a month before the October 2017 off-campus slaying of Brayan Andino, another incident linked to MS-13 erupted at the edge of the San Fernando Valley campus.

At least two MS-13 members, including two former Panorama students, are suspected of stabbing and wounding a student as he was leaving school, officials acknowledged.

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