AUSTIN (KXAN) — University of Texas police are investigating after finding shell casings and a cryptic note left on campus.

Two casings were found in Parlin Hall. A third casing was found in Batts Hall.

One of the casings came with a handwritten note. The word “triggered” was written in red ink.

With the start of the school year came the new campus carry law allowing students to carry handguns on campus. When classes resumed at the University of Texas, students and staff were met with an influx of protests and rallies regarding campus carry.

“It’s supposed to be a safe space but I don’t feel safe,” Mia Barrera, a sophomore UT student said of campus carry. “Why give them guns? Especially when a school is supposed to be a safe place. It doesn’t feel very safe knowing that there are kids who can bring guns on campus.”

The group, Cocks not Glocks, asked anyone against the concealed carry law to wear adult sex toys on their backpacks through Labor Day. Three UT professors also attempted to keep guns out of their classrooms by suing the university. Referring to Campus Carry legislation as “overly solicitous” and “dangerously-experimental,” the professors pointed to more than 20 shootings on college campuses nationwide in 2015. They lost their lawsuit.