Published: Oct 18, 2012 4:56 PM EDT
Updated: Oct 19, 2012 6:31 AM EDT

PHOENIX (AP) - A Phoenix man accused of dressing his nephew in a sheet, sending him into a busy street with a fake grenade launcher, and filming the teen as he pointed the phony weapon at passing cars has pleaded not guilty.

A Maricopa County Superior Court spokesman says 39-year-old Michael D. Turley entered the plea Thursday to falsely perpetuating a terrorism act.

Authorities allege Turley filmed his nephew as the masked 16-year-old pointed a fake grenade launcher at vehicles July 28 in northwest Phoenix.

The film was then posted on YouTube. In it, a narrator says he wanted to see how long it took authorities to respond. Police have identified the narrator as Turley.

Turley also faces counts of endangerment, misconduct involving simulated explosives and contributing to the delinquency of a minor.

He doesn't have a listed phone number. Turley's next court date is set for Dec. 4.