The two people who attacked a kosher market in Jersey City, New Jersey, had a bomb in their U-Haul van so powerful that it could have killed or injured people up to 500 yards away.

FBI special agent in charge Greg Ehrie said at a Monday press conference that the bomb discovered inside the vehicle would have resulted in a large explosion. He also said that the duo had enough bomb construction materials to have built a second explosive device, according to NJ.com.

The gunmen, 47-year-old David Anderson and 50-year-old Francine Graham, were killed during a shootout with law enforcement on Dec. 10. The violence that day began when the two fatally shot Jersey City Police Department Detective Joseph Seals, 40, in the head. From there, the pair headed to a nearby kosher market and killed three civilians.

Once the scene was cleared, investigators found the U-Haul van that the couple was in possession of and discovered an unexploded but viable homemade explosive device.

“I do this because my creator makes me do this and I hate who he hates,” read a note that was found along with the bomb.

The ideology of Anderson and Graham was partially inspired by the Black Hebrew Israelite movement, the members of which believe that they are the true decedents of the ancient Israelites and God’s chosen people, not practitioners of Judaism. Despite the connection or possible inspiration, authorities believe the two worked alone in the attack.

The Southern Poverty Law Center said of the religion that “there is a rising extremist sector within the Hebrew Israelite movement whose adherents believe that Jews are devilish impostors and who openly condemn whites as evil personified, deserving only death or slavery.”

Prior to the Jersey City attack, Anderson and Graham had also researched attacking a Jewish community center in Bayonne, New Jersey.

Authorities on Monday said that the two planned for more bloodshed in hopes of sowing fear in the Jewish community. U.S. Attorney Craig Carpenito called the attack “profoundly un-American” and an “evil and cowardly act.”

“We know now that they planned greater acts of mayhem on both communities,” he said.

According to Carpenito, video from the kosher market recorded Anderson saying, “They stole our heritage, they stole our birthright, and they hired these guys to stop us.”

Authorities also said that the duo were suspects in two other crimes prior to the Jersey City attack. The first was when they fired two bullets at a Jewish person driving a vehicle near Newark. Although the back window of the car was shot out, no one was injured in the attack.

They are also accused of killing taxi driver Michael Rumberger on Dec. 7. Investigators said they bludgeoned him and then shot him in the head, leaving his body in the trunk of his car. Rumberger's blood was discovered on a bible belonging to Anderson and Graham.

The two had traveled to Ohio, and Graham legally purchased the weapons used during the kosher market attack. While there, they also trained on how to use the guns, although Anderson had previously served in the Army Reserve. Anderson was not able to purchase the weapons because he is a convicted felon who has spent time in prison on multiple gun charges.

The FBI is investigating the shooting as an act of domestic terrorism.