The Hall County, Texas blue alert that alarmed everyone, explained

Just before 5:00 a.m. in Texas, people across the state were pulled from their slumber by an unexpected alarm. It was a blue alert, something intended to aid authorities in finding people that are suspected in a crime related to injuring law enforcement. The alert went out to search for a 33-year-old in Memphis, Texas, a part of Hall County, after a police officer was injured in a shooting Thursday night.

Recipients of the blue alert were warned to look out for 6-foot-2 Seth Altman, but told not to approach him and instead call the authorities. The system is designed to warn residents of potential public safety issues, including the more common AMBER Alerts or Silver Alerts for missing people.

But for a lot of Texans, the message was a jarring way to wake up.