Additional police were sent to Jessica's school, said Lynn Setzer, spokeswoman for Jeffco Public Schools. The district has its own security officers at other middle schools and high schools.
Steve Saunders, a spokesman for nearby Adams County schools, said the district is trying to strike a balance between reassuring students and their parents that they are safe, while encouraging them to be vigilant.
Saunders said the district has security officers at all middle schools, but not elementary or high schools. He said the district will seek more help if authorities believe it is warranted.