Benjamin Morrow was found dead with white supremacist literature and the ingredients for a notorious bomb known as the “Mother of Satan.”

Morrow, 28, died in an explosion in the kitchen of his Beaver Dam, Wisconsin, apartment on March 5. His home was filled with bomb-making substances so volatile that firefighters chose to destroy the 16-unit apartment block in a controlled blaze, rather than let Morrow’s neighbors continue to live in the building. A search warrant unsealed last week revealed that Morrow kept white supremacist literature in his home. Investigators’ application for a second warrant suggests that Morrow had plans, announcing that he was clearing out a rented storage locker just hours before his death.

Kevin Heimerl of the Wisconsin Department of Justice called Morrow’s apartment a “homemade explosives laboratory.” When they responded to reports of an explosion at the home, investigators passed “a one gallon metal container of acetone,” an investigator told a judge in a newly unsealed warrant application.

Acetone is an explosive substance and ingredient in the “Mother of Satan”: a volatile bomb used by terrorists in ISIS attacks in Manchester, England, and Paris, France, in recent years.

Also sitting in plain sight where two white cardboard boxes stamped with the words “mix it, shake it, shoot it,” and three more packages labeled “sonic boom,” Heimerl testified, adding that he suspected the boxes contained materials that would explode when combined. Investigators also found pipes and pipe caps in the apartment.

When they entered the kitchen, investigators found Morrow dead in front of a still-lit stove. An “overpressure blast” had destroyed much of the room, blowing out the doors and windows and burying Morrow under the collapsed ceiling. Containers with more chemicals were spilling out an open refrigerator door.

The scene was so volatile that authorities barred the rest of the apartment building’s residents from re-entering their homes, and burned the entire building to the ground in a 1,600-degree controlled blaze overseen by 100 firefighters. Residents left their valuables inside. One of Morrow’s neighbors told the Wisconsin State Journal he planned on digging through the rubble to find a dead relative’s World War II dog tags, which had been left inside to burn.

At the time of the fire, the contents of Morrow’s apartment remained a mystery. But an unsealed warrant describes Morrow as building a terrifying arsenal.

In addition to more bomb-making materials, Morrow also had a collection of guns and accessories including a rifle scope, masks, vests, a ballistic helmet, and thousands of rounds of ammunition.

Morrow also had “white supremacist material” in his bedroom, the warrant said.

Beaver Dam police said the white supremacist literature didn’t necessarily mean Morrow was a white supremacist.

“It does cause me some concern but I want to make very clear just because Mr. Morrow was in the possession of this material, does not categorize in any particular light,” Lt. Terrence Gebhardt told CBS 58. “He could have been an individual that was doing research.”

But state investigators suggested the opposite. In an application for a search warrant, Heimerl raised the possibility that Morrow had worked with or been inspired by others, pointing to the white supremacist literature when a judge asked about “propaganda that raises concern for this kind of collaborative work.”

The investigator who swept Morrow’s room described the literature as relating to white supremacist groups that “will involve multiple members” in potentially violent activities. He did not specify which groups were named in the literature.

Members of Morrow’s church community have pushed back on the idea that Morrow built the bombs in his bedroom and kitchen, for which investigators found handwritten instructions.

“I’d love to defend Ben because he has been described as a bomb maker and he’s not a bomb maker,” Rev. Jerry Marsden, the pastor who conducted Morrow’s funeral told the Associated Press. “He wasn’t a recluse as some have said he is. He was far from that.”

In an obituary, Morrow’s family described him as a religious man, who grew up homeschooled and later studied pre-pharmacy, math, and chemistry at Pensacola Christian College in Florida. The search warrant revealed Morrow had a Bible among his white supremacist literature and bomb-making material.

When he wasn’t building bombs, he worked as a quality control technician at Richelieu Foods, according to his LinkedIn profile. His coworkers told investigators Morrow sometimes came to work with an unpleasant smell on his clothes.

“Some of those co-workers reported that it was common for Benjamin Morrow to arrive for work and he had an odor emitting from his person that co-worker’s described as smelling like moth balls,” Heimerl told a judge in an application for a second warrant. “Those co-workers further stated that they had made comments to Benjamin Morrow about the fact that they could smell moth balls on him.”

Mothballs are made of flammable chemicals, which may explain the smell.

The second warrant application reveals that police were interested in the contents of a storage unit Morrow rented. On the morning of the fatal explosion, Morrow visited the storage company “and notified the business that he would be moving his personal property out of the storage unit by the end of March,” Heimerl told the judge in the warrant application, speculating that Morrow might have rented the storage unit to keep strong-smelling chemicals from his home.

The second warrant, the findings of which are not public, also extend to Morrow’s computers, flash drives, and phone. The records could reveal where Morrow received the white supremacist literature—and whether he was acting alone.

“I am aware that a person could work solely to connect this type of manufacturing homemade explosives themselves,” Heimerl said. “But I am also equally aware that individuals oftentimes communicate, inspire and engage with other persons to manufacture homemade explosives.”