Alex Christopher Castillo, 30, was arrested at the Athens-Clarke County Library on Thursday afternoon after he allegedly made social media threats to kill police, authorities say.
A department-wide email was sent advising Athens-Clarke County police that Castillo used Facebook to allegedly make the threat, and an officer who works security at the library knew the homeless man frequently goes there to use the computers, police said.
The officer alerted library staff to the alleged threat, and one of the employees alerted the officer Thursday that Castillo was there.
Castillo was arrested on an outstanding warrant and was barred from the library for two years, police said.