Uvalde School Shooting: One Year Later, Unanswered Questions Remain.

Chief National Investigative Correspondent Mark Albert visited Robb Elementary in Uvalde, Texas, almost a year after a former student killed 19 students and two teachers using an AR-style weapon. The community is still mourning, and the Hearst Television National Investigative Unit's "Securing Our Schools" series aims to investigate school security concerns and unique district safety initiatives.