Warning: Story contains graphic image(s) & content

Former NFL offensive lineman Jonathan Martin has been taken into custody after posting a disturbing image to Instagram, according to ABC News' Matt Stone.

Here is the picture posted on Martin's Instagram story, obtained by various outlets. The account is private, but verified:

Martin, who has claimed he was subjected to bullying in high school and by NFL teammates, tagged Harvard-Westlake (his former high school) in the post. The school closed both of its campuses in Studio City and Beverly Crest, Calif. on Friday in response to the post.

“Last evening, we learned of an Internet post that mentions Harvard-Westlake by name,” the school said in a statement, according to KTLA. "We are working closely with law enforcement and will share more information when we are able.”

The social media handles for Buffalo Bills guard Richie Incognito and Miami Dolphins center Mike Pouncey were included in the image. The two players were found to have harassed Martin during a bullying investigation with the Dolphins in 2014. Martin also tagged two others who apparently attended Harvard-Westlake at the same time he did.

The disturbing post comes two weeks after 17 people, including students and staff, were shot to death at Marjory Stoneman Douglas High School in Parkland, Fla.

Martin spent three seasons in the NFL after being drafted in 2012. He retired after the 2014-15 season.