Texas mass shooting: Uvalde school district had security measures in place prior to tragedy

"Those proponents include four officers, including a chief, a detective and two officers within the school district; partnerships with local law enforcement agencies; security staff that patrols door entrances and parking lots at secondary campuses; case managers and social workers on UCISD campuses; licensed counselors; threat assessment teams; social media threat monitoring; a visitor management security system; canine detection services; motion detectors and alarm systems; perimeter fencing at Robb and other schools; security vestibules and outside buzz-in systems; security cameras; a locked classroom door policy; staff and student training; and a threat reporting system.

The district states that it uses a service called Social Sentinel "to monitor all social media with a connection to Uvalde as a measure to identify any possible threats that might be made against students and or staff within the school district.""