HAMMOND, Ind. (CBS) — The mayor of Hammond, Indiana was indignant Wednesday after he said a 17-year-old girl was released from custody just a day after making a social media threat to “shoot up” her school.

Mayor Thomas J. McDermott Jr. issued a letter to the office of Lake County, Indiana Prosecutor Bernard Carter, requesting that the girl be fully prosecuted as an adult. McDermott wrote that the girl was set free by a Lake County Juvenile Court Judge within 24 hours of the threat.

In the letter, McDermott wrote that the student had made a social media threat to “shoot up the school” that included a photo of a weapon.

McDermott said the incident happened last week. A social media post threatened gun violence at Hammond High School on Wednesday, Sept. 11, and forced a lockdown for all public schools in Hammond.

McDermott wrote that Hammond police took the threat very seriously, with many officers being pulled off their regular schedule to alleviate any possible threat to students at schools around Hammond.

The Hammond Fire Department also had a truck at every school for two hours in case of trouble, until an all-clear message was issued, McDermott wrote.

“Dozens of panicked parents were outside the school waiting anxiously on whether their children would be going home with them or worse,” McDermott wrote. “Yet, during this entire time, the female student sat in her classroom watching the pandemonium around her with no remorse.”

McDermott wrote that due to the seriousness of the matter, the lost hours for the police and fire departments, and the panic that ensued, he wants the girl who issued the threat waived to adult court and “appropriately charged and prosecuted.”

“I noticed recently that other threats around the country are being prosecuted and punished seriously, and I believe it to be very important that Lake County do the same to deter such behavior in the future,” he wrote.

McDermott also expressed indignation at the situation in a Facebook post accompanying the letter, characterizing the fact that the girl was set free as a symptom of “what’s wrong with America nowadays.”

“Within 1 day of making terrorist threats, she was back on our streets,” he wrote. “But I’m sure she had a stern lecture and will never repeat such behavior again after that 24 hour stay, right?”