An Arizona high schooler has been arrested for the possession of an improvised explosive device. The family’s housekeeper found a device resembling a bomb in the teenager's bedroom and brought it to a local fire station.

According to AZ Central, Joshua Prater, 18, a senior at Marcos de Niza High School, was arrested on Wednesday afternoon on suspicion of misconduct involving weapons and for possessing the IED.

The housekeeper, who was not named, discovered the weapon while cleaning Prater's bedroom. She also found other suspicious bomb-making materials. After photographing the other materials, she turned the IED over to the Tempe Fire Station around 2:30 p.m. local time.

"They had it X-rayed, they saw it was a valid IED," Tempe Police Sgt. Mike Pooley told Fox Phoenix. "It was something that wasn't big, but could cause serious injuries and the death of someone."

Officials at the fire station quickly called the police, who confirmed that the housekeeper did indeed find an explosive IED.

"There was fuse that was coming out from the device which would be how you light it and it would cause the fuse to go in there and explode," Pooley told AZ Family. "The bomb was ready to go. It was active. All it needed was the trigger."

According to the Phoenix New Times, the IED was constructed out of an empty carbon-dioxide cartridge, which had been filled with explosive powder, match heads and fireworks. 

Prater reportedly told police that he built the IED eight years ago and that he was unaware it still contained explosive material.

Prater is facing felony charges and is being held on a $10,000 bond.