By Emmy Sandstedt, For the Mirror

Joshua Brooks, 38, was charged with possession of an incendiary device after a vehicle exploded on a residential street in Federal Way on June 5. He pleaded not guilty during the initial arraignment, which took place June 21.

An investigation into the explosion was conducted by the Federal Way Police Department, who uncovered evidence of homemade explosives that likely caused the blast in the 29800 block of Fourth Avenue SW.

Police put a restraining order against Brooks after he was found with the bomb after the initial explosion.

Responding officers had contacted the owner of the Toyota 4Runner, identified as Brooks. He initially claimed he was unaware of what caused the explosion and told police nothing had been in the car besides spray paint.

The debris from the explosion was scattered across neighboring properties. The windshield of the vehicle was found on the roof of a home 293 feet from the original point of detonation. The widespread fall of debris outward from the detonation point indicated the explosion originated inside the vehicle.

The Bomb Technicians advising on the investigation believed the damage was the result of explosives rather than a car fire, based on the debris patterns.

Police determined that Brooks had been manufacturing homemade explosives, due to ingredients found in his room. Triacetone Triperoxide, a homemade explosive known as TATP was found in large quantities. Common ingredients for explosives, including acetone and acid, were found in common areas of the house and in another vehicle on the property.

TATP explosives have been used in multiple terrorist attacks, due to the accessibility of the ingredients, according to an article released by McGill University. These ingredients can be found in readily available products, such as nail polish, which can be purchased at many stores.

His mother, in a written report to the police, stated that Brooks had a history of depression and addiction to prescribed medication, and said she believed he had previously alluded to wanting to commit suicide. His father added that he enjoyed shooting guns and mixing chemicals to produce a reaction.

Besides the explosive ingredients, 11 guns were found in various locations on the property, including in Brooks’ room.