Ex-NFL player Jonathan Martin taken into custody in connection with Instagram post that closed Harvard-Westlake

Former NFL player and Harvard-Westlake alumnus Jonathan Martin was taken into custody Friday in connection with an Instagram post that displayed a shotgun and referenced the school by name, a source told the Los Angeles Times.

A picture of the weapon with the words Harvard Westlake written across the barrel triggered the school’s closure on Friday, according to three sources.

The image, which referenced revenge and suicide as the only options for a victim of bullying, was posted to a verified Instagram account belonging to Martin, the former Miami Dolphins’ offensive lineman who accused teammates of bullying in 2013.

The post on Martin’s page led Harvard-Westlake officials to close the school’s campuses in Studio City and Beverly Crest, the sources said.

The sources spoke to The Times on condition of anonymity because they were not authorized to discuss the case with the media. A Los Angeles police spokesman declined to comment on the specific post that triggered the incident.

In a message sent to students Friday morning, school officials said they were made aware of a “disturbing social media post that mentioned Harvard-Westlake by name” late Thursday night.

“The safety of our students, faculty, and staff is always our primary concern. So, out of an abundance of caution, we made the decision to close school today,” the email read. “The school’s private security team is working with the Los Angeles Police Department, which is present on both campuses. With these precautions in place, we believe there is no imminent threat to our campuses or our school community.”

A school spokesman did not respond to a request for comment. Earlier on Friday, an LAPD spokesman said the post that triggered the closure did not make a “direct threat” against the school.

Martin graduated from Harvard-Westlake in 2008 and joined the Dolphins in 2012. But during his second year in the NFL, he became the center of a scandal alleging harassment and bullying on the part of his teammates, including offensive linemen Richie Incognito and Mike Pouncey. Both players’ verified Instagram accounts were tagged in the post.

“When you’re a bully victim & a coward, your options are suicide, or revenge,” read the text of an Instagram story posted to Martin’s verified account.

Martin retired from the NFL in 2015 following a back injury, after stints with the San Francisco 49ers and Carolina Panthers. That same year, he detailed his struggles growing up in Los Angeles and said in a series of Facebook and Twitter posts that he had attempted suicide while playing in the NFL. He also said he had been uncomfortable at Harvard-Westlake as “one of just a handful of minorities” on the campus.

“You learn to tone down your size & blackness by becoming shy, introverted, friendly, so you won’t scare the little rich white kids or their parents,” he wrote in 2015. “Neither black nor white people accept you because they don’t understand you. It takes away from your self-confidence, your self-worth, your sanity.”

Matt Yam, one of the sports editors at the school’s student newspaper, said there were roughly 100 students on campus when the alert went out, but few, if any, panicked.

“Honestly, it’s not bad. Everybody is calm. A lot of people are leaving now. Everything is under control,” said Yam, 18. “People don’t seem too worried.”

The incident comes on the heels of a series of threats that have sparked police responses at Southern California schools in the days after a gunman killed 17 people at a Parkland, Fla., high school.

Last week, Los Angeles County sheriff’s deputies arrested a 17-year-old student and his older brother after a school resource deputy says he overheard the student threatening to “shoot up” El Camino High School in Whittier. Deputies recovered several rifles, handguns and high-capacity magazines at the student’s home.

“We cannot afford to not act on any threat,” Los Angeles County Sheriff Jim McDonnell said in an interview with The Times on Friday about the rash of school threats. “You have to be hyper-vigilant on them because God forbid, if one of them is an actual someone willing to do something, you cannot take that chance.”

Earlier this week, a 27-year-old Norco man was arrested after police said he posted on Facebook that he intended to shoot people at a local community college. A search at Jacob Ryan McBain’s home turned up two loaded AR-15 rifles, two loaded handguns and a large amount of ammunition in his bedroom, authorities said.

Long Beach Police arrested two teenagers this week on suspicion of making criminal threats to harm students, and a 14-year-old student at Torrey Pines High School in San Diego was detained Thursday, suspected of making verbal and written threats.

Mike Dorn, executive director of Safe Havens International and a schools safety expert, said schools across the country are dealing with a surge of reports about threats as parents and students become more vigilant about safety issues.

“Kids who saw or heard something before and ignored it are now reporting what classmates say,” he said.

james.queally@latimes.com

Follow @JamesQueallyLAT for crime and police news in California.

UPDATES:

2:25 p.m.: This article was updated with new comments from Los Angeles County Sheriff Jim McDonnell and a schools safety expert.

12:55 p.m.: This article was updated with information about Martin being taken into custody.

11:55 a.m.: This article was updated with information about the origins of the threat.

9:05 a.m.: This article was updated with more details about other related incidents.

8:30 a.m.: This article was updated with comments from a student on campus.

This article was originally published at 8:15 a.m.