Circling back, the main area of concern is the image you posted. Tighten things up there for sure. Also absolutely make sure everyone is searched and tell people if they "see something, say something" to the shield / security team. Anyone acting really weird at camp, anyone super highly agitated or agitating during the march, anyone wandering around alone at camp or caught with a phone, etc. You are going to want to clamp down hard on this for everyones good.