The Patchogue-Medford School District says bullets found inside the high school back in December were placed by a district employee.
Some parents even say they believe the employee planted the bullets as a way to get school officials to improve security.
"I do agree in the sense that he did want to open up everyone's eyes," said Jen Lucas-Cohen. "He did want to say, 'Oh look, it's lacking security. Your kids are not safe. This is what they should or shouldn't do.' I can understand his side."
Parents also tell News 12 that the incident did spark changes in security. They say each student now passes through a metal detector when entering the school and their bags are searched by school security.
In an updated letter sent to the community on Tuesday, district officials said both the district and Suffolk County police conducted investigations into the matter.
The investigations were recently closed in late February, but an investigation by the Suffolk County District Attorney's Office remains open.
Officials say the individual responsible for placing the bullets in the school is no longer employed by the district. However, no additional information can be made available because this is a personnel matter, officials said.
Some parents, however, still want to know which employee brought the bullets to the school.
"I don't think we'll ever have that answer but that's a scary, scary thing because now you're not dealing with a child, you're dealing with an adult," said Michelle Barke.
The district concluded the letter saying, "The safety and well-being of our students and staff is our highest priority. We will remain vigilant in our safety and security efforts and ask our community to join with us in this effort. If you hear or see anything that you believe might be a threat or cause danger to students, staff or District property, please contact District administration, a building principal or teacher, or law enforcement immediately."