Last Sunday, a 15-year-old student at Alan B. Shepard High School in Palos Heights was arrested for posing with an AK-47 assault rifle and making threats toward the high school on Snapchat.

The Cook County Sheriff’s Office was alerted to the threats on Sunday and made the arrest later that evening. The student has been charged with a felony count of disorderly conduct.

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According to the sheriff’s office, there were no weapons found at the boy’s home. The Sun-Times reports that the photos were taken elsewhere and with an unidentified person who who has a valid Firearm Owners Identification card.

This arrest happened just days before the tragic shooting at Marjory Stoneman Douglas High School in Parkland, Florida that has claimed 17 lives.

The Superintendent of Community High School District 218 where Alan B. Shepard is a part of, sent out a letter to parents following the Parkland shooting.

“We are all shocked and horrified at the school tragedy that occurred in Florida,” the statement read. “These types of events have become all too familiar in recent years.”

“Today, the principals at our high schools read an announcement to our students that encouraged them to be part of the solution and not part of the problem. We encouraged students to always and immediately share any concerning information they may have with an adult – whether it is a parent, teacher, administrator, or security person.”

“Please talk with your sons and daughters about this message and please encourage them to report any concerns or fears they may have.”

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While contacting authorities after seeing pictures posted online is one way to help prevent these kinds of tragedies, there can be other warning signs out there as well.

In Washington, a grandmother turned in her grandson after reading details in his journal about “detailed plans to shoot students and use homemade explosive devices at ACES High School.”

Palos Heights student arrested for making threats and posing on social media with an AK-47 (AP Photo/Seth Perlman)