Mr Green supposes that this is because action games require players to do a lot of things at once look for new enemies, shoot old ones, dodge bullets and so on.
The man told police he attended the Batman film in Saco, Maine, on Saturday with a loaded gun in his backpack and told authorities he was traveling to Derry, New Hampshire, to shoot a former employer.
With other countries, notably China, finding new ways to sink ships and shoot down planes and satellites, the QDR considers a new generation of long-range weapons such as unmanned bombers launched from aircraft carriers and long-range cruise missiles fired from submarines.