"An investigation initiated in May 2025 uncovered evidence that the misconduct began in 2021 and continued for at least two years with the then teenage boy," the sheriff's office wrote.
The Greenville Police Department added in a separate post obtained by PEOPLE and shared on Facebook that "some of the alleged criminal activity had occurred within the jurisdiction of the City of Greenville."
The police department confirmed that Callaham had previously worked as an elementary school teacher, writing, "The investigation revealed that Callaham engaged in an inappropriate and unlawful relationship with a 14-year-old male. Based on evidence collected, Greenville detectives obtained arrest warrants for multiple offenses committed within our jurisdiction."
In addition to the ACSO's charges, the suspect has also been charged with eight counts of criminal sexual conduct with a minor and four counts of unlawful conduct towards a child by the Greenville Police Department.
The ACSO said on Instagram that the suspect and the teenager's relationship had "intensified as she reportedly signed the student out of school, transported him to practices, and served as a supervisor for after-school activities."
"These repeated interactions led to a prolonged pattern of abuse, which was corroborated by search warrants and ongoing cooperation with the victim’s family," the sheriff's office added.
"According to investigators, the victim made the decision to come forward after turning 18, following time spent processing the experience and trauma associated with the abuse," the post stated.
The sheriff's office also confirmed that a "parallel investigation is currently underway by the Clemson City Police Department."
Callaham has since resigned from her teaching position "and Anderson School District Five is aware of the investigation and charges made by ACSO detectives," the post noted.
Following Callaham's arraignment on the ACSO's charges, "she will be transported to the Greenville County Detention Center for charges filed by the Greenville Police Department," the police department wrote on Facebook.
