Uvalde County Sheriff Ruben Nolasco rushed toward Robb Elementary School when calls came in that a man was firing his gun after crashing his pickup truck on May 24. He was one of the 376 officers who went to help children and teachers. But, unlike the vast majority, he had the rank to easily take charge, he had vital information about the shooter and a call about victims in a classroom, and others looked to him as a commander on the scene with up-to-date information. CNN's Shimon Prokupecz reports.