Campus Alert Archive
Mt. SAC

Mt. SAC's Stabbing Alert Lands 40 Minutes Late and Triggers a Fall-Long Reckoning Over Campus Safety

CAstabbingemergency notificationmedium confidence
Confirmed Threat

On the morning of Wednesday, September 20, 2023, a physical altercation in Building 26B at Mt. San Antonio College escalated into a stabbing at approximately 11:30 AM PDT, with the victim suffering torso and neck wounds. The campus-wide Mt. SAC Alert was not sent until roughly 12:10 PM — a 40-minute response-time gap that triggered a fall-long student and faculty backlash about the college's emergency notification practices. Suspect Gavin Flores, 18, was arrested on suspicion of attempted murder; classes in Buildings 26A, 26B, and 26D were canceled for the rest of the day.

Alerts
1
Response
—
Killed
0
Injured
1
Institution
Mt. San Antonio College
Community College · CA
~55,000 studentsRaveMt. SAC Alert
Confirmed Timeline

Alert Sequence

1 message in sequence · 1 verified verbatim

INITIAL ALERTSMS
Verified verbatimSAC Media (Mt. SAC student newspaper) — published the verbatim Mt. SAC Alert in its fall 2023 campus-safety investigation156 chars
MtSAC Alert: An altercation resulted in a physical attack at about 11:40 am. Police investigating. Suspect in custody. Witnesses please call (909) 274-4555.
Reports the incident as occurring 'at about 11:40 am' — Mt. SAC's own timestamp; the LA County Sheriff's Department logged the 911 call at approximately 11:30 AM PDT, so the alert's stated time is itself 10 minutes off the actual incident
The alert ran approximately 40 minutes behind the incident — Professor Shiloh Blacksher, who was on scene, called out the lag at the September 21 Academic Senate meeting along with construction obstructing EMS access and slow trauma-counselor response
The message uses present tense ('Police investigating', 'Suspect in custody') because by the time the alert went out, Gavin Flores was already in custody — the alert was less a warning than a notification
Critically, the alert did NOT instruct students in Building 26 to evacuate, despite the bloody scene still being active on the second floor of 26B
Mt. SAC primarily uses Rave-based SMS and email; the same message was simultaneously posted to the college's main Facebook and X accounts
Context

Background

Mt. San Antonio College is the largest single-campus community college in California, serving roughly 55,000 students annually at its 421-acre campus in Walnut, eastern Los Angeles County. The September 20, 2023 stabbing began as an altercation over a female student between her current boyfriend and an ex-boyfriend, all three of whom were Mt. SAC students. According to LASD, the ex-boyfriend — Gavin Flores, 18, of West Covina — was the aggressor and pulled a knife, stabbing the female student's current boyfriend multiple times in the torso and neck on the second floor of Building 26B at 1100 N. Grand Avenue; the female student had previously notified Mt. SAC's Title IX office and police about harassment and stalking by Flores and was in the process of filing a restraining order against him. The 18-year-old suspect, Gavin Flores of West Covina, was taken into custody on suspicion of attempted murder and held on $1 million bail; charges were later reduced and he pled no contest to a misdemeanor violation of Penal Code § 626.10 for one year of summary probation. The bigger story, however, became the Mt. SAC Alert response time. The campus-wide text alert went out roughly 40 minutes after the incident, did not instruct anyone in Building 26 to evacuate despite an active bloody scene, and timestamped the attack at '11:40 am' — itself 10 minutes off the actual incident time. Faculty and students raised the issue at the September 21 Academic Senate meeting, and the lag became the focal point of a fall-long campus-safety reckoning that included concerns from the Deaf and hard-of-hearing community about whether they could rely on the alert system at all, questions about construction obstructing EMS access, and complaints about slow trauma-counselor deployment. By April 2024, Mt. SAC committed to installing additional cameras in response to the cluster of fall 2023 incidents, which also included two sexual assaults, a knife-point robbery, and a separate parking-lot attack. The case is a useful study in how community-college emergency-alert systems can fail not on the side of false positives (swatting, drill confusion) but on the side of operationally-late notifications that arrive after the actual threat has already been neutralized.
Analysis

Key Findings

Mt. SAC's 40-minute response-time lag from a violent stabbing to the campus-wide alert is at the slow end of documented community-college Clery-Act emergency notifications; the Clery Act requires alerts to be issued 'without delay' once a continuing threat is confirmed
The alert's own timestamp ('at about 11:40 am') was 10 minutes off the LA County Sheriff's logged incident time (~11:30 AM PDT), suggesting Mt. SAC's internal incident-tracking does not match the law-enforcement record
The alert did NOT instruct students in Building 26 to evacuate, despite a bloody crime scene still being processed on the second floor — a substantive omission given the building remained occupied during the alert
The incident catalyzed a fall-long campus-safety reckoning at Mt. SAC, including concerns from ACCESS and the Deaf/hard-of-hearing community about whether SMS-only alerts adequately served them
Outcome
Victim hospitalized with stab wounds to torso and neck; survived. Suspect Gavin Flores, 18, of West Covina, arrested on suspicion of attempted murder and held on $1 million bail; on October 1, charges were reduced — Flores ultimately pled no contest to a misdemeanor violation of Penal Code § 626.10 (weapons on school grounds) for one year of summary probation, 15 days of community labor, and search/seizure plus weapons conditions. Classes in Buildings 26A, 26B, and 26D canceled for the rest of Wednesday; campus reopened Thursday.
Provenance

Sources

  1. Student Paper
    Altercation between three people leads to stabbing at Mt. SAC — SAC Media
    sac.media
  2. Student Paper
    Is Mt. SAC safe? — SAC Media (fall 2023 campus-safety investigation)
    sac.media
  3. Student Paper
    Update on Mt. SAC stabbing incident — SAC Media
    sac.media
  4. News
    Student stabbed at Mt. San Antonio College in Walnut; suspect arrested — ABC7 Los Angeles
    abc7.com
  5. News
    Altercation over female student leads to stabbing at Mt. San Antonio College — KTLA
    ktla.com
  6. Student Paper
    Mt. SAC installing cameras amid continuing safety concerns — SAC Media
    sac.media
Tags
community-collegestabbingmt-saccaliforniaresponse-time-lagclery-actattempted-murderwalnutaccessibility-concernsalert-design-failure
Added May 2026Updated May 2026Via ingestion