Trip wires found in Aurora home where police seized bombs, chemicals Tuesday

Michael Grover being held on $1 million bond

AURORA, Colo. - Trip wires and potassium nitrate were found inside the Aurora home where explosives were seized Tuesday.

The home's owner, Michael Grover, was arrested and is being held on charges of possession of an explosive device. His bond was increased from $250,000 to $1 million in court Wednesday.

Grover's hand was bandaged in court.

The explosive devices and bomb-making materials were found by firefighters responding to a small fire in the basement of the home on South Bahama Street and East Louisiana Street around 10:30 p.m. Monday.

According to an arrest affidavit, authorities found fireworks, guns, ammunition and eight pipe bombs on the property. 

The Arapahoe County bomb squad was called in and neighbors were evacuated for safety until about 6:20 p.m. Tuesday.

Aurora police spokeswoman Sgt. Cassidee Carlson described the pipe bombs as "pretty powerful devices" and said bomb techs had informed her they "could have possibly totally demolished the suspect's house and possibly damaged other houses."

Grover told police he devices were not connected to a power source, and he planned to detonate them during the upcoming weekend.

So far, police have not speculated on Grover's motives.

According to the affidavit, potassium nitrate was also found inside. A hazardous materials team was called in to check it out and, in turn, they called a special team from Buckley Air Force Base.

Potassium nitrate, also known as saltpeter, was a key component of gunpowder in the 19th Century. While rendered nearly obsolete by dynamite and TNT, it is still used today in artillery shell detonators, hand-grenade fuses and fireworks, according to a science website. It's also used in fertilizer.

"This is a slow process, we want to do it safely," Carlson said of the investigation at the home during a Tuesday press conference.