MARION — Marion Police Tuesday arrested a Marion man for making terroristic threats.

Police say 21-year-old Treston J. Miller made an online threat to “shoot up” a school in Marion.

Police conducted an investigation which led to Miller being interviewed. During the interview Miller admitted to the investigator that he had made the posts.

According to WSIL-TV, Miller is charged with three counts of making terrorist threats – all Class X felonies. Miller appeared in Williamson County Court Thursday. He is being held on a $1 million bond. He is set to be back in court Aug. 30.

Police continue to investigate this case.