Accused mass shooter James Holmes used homemade napalm, thermite, gasoline, smokeless gun powder, rifle bullets, and a remote-controlled car and a boom box to booby-trap his apartment before setting off on a shooting spree at an Aurora movie theater, prosecutors said in a Colorado court today.

According to an FBI agent, Holmes’s ultimate plan was to create a distraction—bringing police to his home and leaving fewer resources at the Century 16 complex four miles away, where he was carrying out what prosecutors say was a meticulous plan to kill as many people as possible.

“He said he rigged his apartment to explode or catch fire in order to divert police resources to his apartment,” FBI supervisor Garrett Gumbinner testified on the second day of a preliminary hearing in the case against Holmes, a former neuroscience doctoral student at the University of Colorado Denver accused of killing 12 people and injuring 58 others in a shooting spree at a midnight showing of The Dark Knight Rises on July 20.

The intricate, sophisticated booby traps Holmes allegedly planted inside his 850-square-foot apartment on 1690 Paris Street, in a run-down section of North Aurora, resulted in a veritable military powder keg, designed to kill anyone who entered or lived in the building.

Holmes, who was sitting in the courtroom in the Arapahoe County courthouse, staring off into space and showing little interest in Gumbinner’s testimony, told detectives about the deadly contents found in his apartment soon after he was arrested at the back of the movie theater.

In total, more than 120 officers were dispatched to the movie theater; more than 1,000 detectives, federal and local officers, and forensic personnel have been involved in the case since. FBI and law-enforcement agents ultimately spent around 36 hours attempting to identify and clear Holmes’s apartment of the most major IED threats before police could enter.

Discovered inside the apartment was a trip-wire attached from the door to a Thermos filled with glycerine, which was perched on a 45-degree angle over a frying pan filled with potassium permanganate. The combination of the two chemicals would trigger heat and fire, said the agent. Gumbinner said Holmes also laced the floor with ammonia chloride “to scare us”—and to produce copious smoke and a flame that if it ignited the carpet, which was saturated with oil and gas, could set off a huge explosion.

Agents also discovered inside Apt. 10 a pyrotechnic box with six-inch fireworks shells attached to a number of black balls filled with gunpowder, gas, and oil on top of the fridge. Holmes told detectives that the detonator to set off the box was attached to a remote control outside next to a garbage dumpster, a boom box, and a remote-controlled car.

The goal, he told authorities, was to draw his neighbors and police to the devices by setting up loud music. He was hoping that someone would hear the techno beats and go explore—playing with the car, fiddling with the remote, and detonating the explosives inside the building. 

Scattered throughout the apartment were also numerous bottles of gasoline, dozens of explosive devices, and three jars that were mixed with a combination of chemicals that included napalm, ammunition, smokeless powder, and thermite.

Authorities also found the paintbrushes Holmes allegedly used to make the napalm.

During his interview with police, Holmes said he tried to purchase the highly combustible compound ammonium nitrate—often sold in cold packs—but couldn’t locate it in the five or six different stores he searched. 

While in a room at police headquarters, an officer guarding Holmes saw him try to stick a staple into an electric socket while waiting to be interviewed. That same officer saw Holmes moving his hands in a “talking puppet motion” after they were covered with paper bags to test for ballistic evidence. Aurora Police detective Craig Appel also testified that he saw Holmes playing with a Styrofoam cup and “just trying to flip the cup on the table."

Also testifying during the day-long hearing was Steven Beggs, a special agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives, who told the courtroom that his federal agency created a timeline of when Holmes purchased the firearms used in the bloody rampage. Beggs testified that Holmes legally purchased much of his equipment online and at gun shops around Colorado in May, two months before the mass shooting: four handguns; close to 6,300 rounds of ammunition; two pairs of handcuffs; ballistic pants; Kevlar protection for the torso, neck, and groin; and military first aid dressing.

His first purchase, according to the agent, was two six-ounce tear gas grenades from an Internet dealer in Maryland on May 10. Beggs testified that Holmes purchased the guns and ammunition legally and cleared the background checks conducted by the ATF.

On cross-examination, Holmes’s attorney asked Beggs if there was a process in Colorado to screen out whether a severely mentally ill person is purchasing the weapons and ammunition. "No," Beggs replied.

At the same time Holmes was stockpiling weapons, Aurora Police Department detective Tom Welton testified that Holmes created profiles on relationship-seeking sites Match.com and AdultFriendFinder.com. Holmes used his credit card and personal computer to create a profile on Match.com on April 19, 2012. He created the AdultFriendFinder profile on July 5. As a headline for his profile, Holmes used the words, "Will you visit me in prison?"

He visited both of the sites just two days before the massacre.