[Edward]

PHOENIX -- Police have arrested an Arizona man who allegedly filmed his 16-year-old nephew walking city streets dressed in a sheet and carrying a fake grenade launcher, authorities said on Wednesday.

Michael David Turley, 39, was arrested Monday over the making of the video, in which an unidentified narrator says he aims to discover how quickly police in Phoenix would respond following the fatal shooting of 12 people at the screening of the “Dark Knight Rises” Batman movie in Aurora, Colorado, in July.

On the video, it shows that police took over 15 minutes to respond.
I am not so confident I'll be safe from RPG-wielding terrorists covered in bed linen.

I like the point they were trying to make, but I don't think they did it in the right way.
Apparently the filmmaker was arrested, but the actor (his nephew) wasn't.

Turley was charged with knowingly giving a false impression of a terrorist act, endangerment, contributing to the delinquency of a minor and misconduct involving a simulated explosive.

Source: NBC News