Both Surgi and Hughes were also interrogated by the police.
America's crime rate was ranked one of the highest in the world. Elites within the state police were not to be trifled with. After investigating the crime scene, they confirmed the nature of the crime: internal and external collusion.
The state of Arizona was extremely strict in regards to the management of the national park. Even though the area of the national park was huge, the whole place was surrounded by fences. If machines were to be brought in, the only way was to go through several front gates.
The ore excavators could not be hidden and brought inside due to their large size and the security guards controlling every gate. The only way was to place them in the trunks of trucks.
As such, the police determined that without coordinating with the staff or security guards, the machines could not have been brought into the park.