The man had pulled a knife on a boy just outside a screening area, said Elaine Sanchez, spokeswoman for McCarran International Airport.
The child was unharmed and returned to his mother, who was at the airport, Sanchez said. The man was taken to a hospital.
"The system worked," Sanchez said. "As soon as the breach occurred, the police were in place and the system worked."
Two officers were involved in the shooting, said police spokesman Jose Montoya.
