PITTSBURGH (AP) — Authorities say a Pittsburgh college student who sent an anonymous message to a teacher about using a sniper rifle from a rooftop has been charged with making terroristic threats.

Investigators say 18-year-old Carnegie Mellon University student Derek Li sent the email through a class site on Feb. 7.

Authorities say Li told them he copied the message's text from an online discussion board. A university faculty member received the message through an anonymous student feedback section that's used as part of a course.

Li told investigators he doesn't have access to a gun. It wasn't known Thursday if he's retained an attorney.

In a statement sent Thursday to students and staff, interim university President Farnam Jahanian said the message "contained threatening language and deeply disturbing imagery."