The supporters, prompted by a Facebook page, made the signs and wore red - Sexton's color - to show their support.
Superintendent Yvonne Caamal Canul says she's grateful for their efforts.
"The neighborhood was great!" she said. "The people came out, they helped us, they talked to the kids who were hit. And they were very, very supportive and everyone was like "We just can't believe this happened."
Stay tuned to 6 News for continuing coverage of this story and a complete report tonight at 5 and 6.