Nearly a month after closing due to a security threat, the school is reviewing and updating security measures to ensure that the campus remains safe for all students, faculty and staff.

The administration notified students that increased security measures would be put into place.

“You will notice a heavier-than-normal security presence, and there will be additional security measures that you will not see,” President Rick Commons said in an email sent to students the day after the school closure. “Increased security measures will be in place at Harvard-Westlake for the foreseeable future.”

Both the Upper School and Middle School closed Feb. 23 due to a security threat from a social media post by former NFL player Jonathan Martin ’08. Martin posted a picture to his Instagram account of a shotgun and ammunition and included the hashtag #HarvardWestlake. The post also tagged four people: two of his high school classmates and two of his former Miami Dolphins teammates.

The school handled the security threat effectively and according to protocol, police officer and security guard Jim Wirth said. After notifying the school community of the threat and closing both campuses, the administration worked with local police, who obtained a search warrant for Martin, according to Wirth.

Police detained Martin, who was in Los Angeles, later that day. He had a loaded shotgun, knife and ax when he was arrested, according to court documents filed after Martin was taken into custody that were obtained by TMZ Sports.

“If anybody gives us a credible threat, it’s looked at,” Wirth said. “We’ve been notified of alumni and some people that have become threats or have threatened a teacher. We have pictures and we know to watch for those people when they come on campus.”

Although Head of Communications & Strategic Initiatives Ari Engelberg said he cannot disclose the specifics of all of the new security measures, he said the school continues to prioritize the safety of everyone on campus.

“What we didn’t want is for students to feel like now suddenly they’re being watched all the time or it was impossible to move around campus,” Head of Upper School Laura Ross said. “We didn’t want it to feel that way, but we wanted to make sure we had a great handle on who’s coming on and off campus.”

Some of the new efforts by school security have been more visible. In a Chronicle poll of 373 students, 55 percent said they noticed more security measures on campus recently.

Security guards are enforcing the rule for seniors who leave campus during the day to sign out and for juniors to present a pass from Upper School Student Discipline and Attendance Coordinator Gabriel Preciado to security when leaving campus before the end of the school day.

Additionally, students walking to Hamilton Gym are now required to sign out at the security kiosk.

Visitors, including Harvard-Westlake parents, coming on to campus have been stopped by security guards before proceeding onto campus, and Wirth said rules for Studio City community members using the track were put in place in recent years. Brief background checks are carried out on neighbors who want to use the track. They are then given identification cards that allow them to use the facilities, Wirth said.

Another factor that the administration is considering is the accessibility of the upper school campus compared to that of the Middle School. While the Middle School only has one main entrance, the Upper School has five separate entrances that stay open during the school day.

“It would be a huge undertaking to have a gate like they do at the Middle School, where everything’s closed all the time, but I think that’s certainly something we’ll probably look at,” Ross said.

After processing the events that led to the school closure and assessing the school’s security efforts, Commons said he was reassured by the community’s response.

“I was really impressed with the way in which students and faculty worked together to be efficient in clearing the campus and getting people home safely,” Commons said. “It was really heartening for me to see how people reacted calmly but seriously and efficiently without people being at all selfish.”