A police officer stands guard outside the scene of a mass shooting in Plano, Texas, on Sept. 10, 2017.
A police officer stands guard outside the scene of a mass shooting in Plano, Texas, on Sept. 10, 2017. LM Otero AP
A police officer stands guard outside the scene of a mass shooting in Plano, Texas, on Sept. 10, 2017. LM Otero AP