Austin ISD will increase security at its schools this week in response to a May 24 shooting that killed 19 children and two adults at Robb Elementary School in Uvalde.

Superintendent Stephanie Elizalde met with the district’s police department to discuss increased safety measures during AISD’s last days of school and graduation ceremonies, according to a letter sent to district families on May 25.

Additional police officers will be on patrol at AISD campuses this week. High school-based officers will also move to cover elementary and middle schools after their home campuses are released. Officers are working with individual campus administrators on safety and emergency protocols. Security will also be increased at AISD’s graduation ceremonies, which will take place this week and next week.

Entry to AISD campuses is restricted and only accessible from outside by authorized key cards, Elizalde wrote. Police officers monitor social media for online threats, and all campuses practice escalating safety protocols. The district has already invested $2 million from a Texas Education Agency grant to install bullet-resistant material in the entryways of all AISD schools—a project that should be completed this summer, according to the letter.

The 2017 school bond also allocated $22 million for security improvements, including security camera upgrades and electronic intrusion detection at AISD campuses and facilities.