A 21-year-old illegal immigrant residing in the sanctuary city of Rochester, New York, was arrested on Tuesday for allegedly threatening to shoot up a local high school via a social media account. Upon further investigation of the suspect's residence, officers recovered a shotgun.

"I'm coming tomorrow morning and I’m going to shoot all of ya b******," the suspect allegedly wrote on East High School's Facebook page on February 16, two days after the South Florida school shooting.

The suspect was arrested four days after the threat was initially posted from the anonymous account she created in January. The 21-year-old was charged with making "terrorist threats," which is a felony.

"(The suspect) was arraigned in Rochester City Court and bail was set at $15,000," the Democrat & Chronicle reports.

As a so-called "DREAMer," the suspect is protected from deportation by the Deferred Action for Childhood Arrivals program. It has been confirmed that the suspect is enrolled in the Rochester City School District as a student, but is not a student at East High, the school she threatened. It remains unclear why the woman was still enrolled at a high school at the age of 21, or in which school she was enrolled.

“Sadly, in wake of the recent Parkland, Florida tragedy, schools across the country have been grappling with social media threats intended to instill fear and anxiety,” said East High School superintendent Shaun Nelms. “While we cannot comment on this particular police investigation around a threat made to East, I want to stress how fortunate we are to be part of a community in which the police department works closely with schools to ensure the safety of the entire school community.”

“We remain very grateful to the Rochester Police Department for their partnership and for keeping us well informed throughout the entire process. Their presence on campus last week and their guidance on how to best keep staff and students safe during this efficient, successful police investigation reiterates their ongoing support. As always, the safety of students and staff is our top priority," added Nelms.

UPDATE: The suspect attends Edison Tech High School and is enrolled in a special education program. According to the suspect's parents, she "has very low cognitive capability and is incapable of carrying out the sort of threat she's charged with making," reports USA TODAY.