Villasenor was arrested Friday after police and the FBI narrowed the number of suspects down.
Olivieri said he is going to try to get the department reimbursed by Villasenor for the investigation and resources used to look into the threats, the Times reported.
Villasenor admitted to sending the email, NBC News reported.
Police, however, also used Villasenor's alleged false threats as a learning experience, to see how infrastructure put in place by festival organizers would work in a real-life situation.
A new command center was built on the fairgrounds where police, fire and other first responders can coordinate. There are also extra video cameras and metal detectors installed. In addition, employees and contractors' badges are scanned before they enter the fairgrounds, the Times reported.