JERSEY CITY, New Jersey (AP) — The couple who burst into a kosher market in Jersey City with assault weapons appear to have acted alone even though they had expressed interest in a fringe religious group that often disparages whites and Jews, New Jersey officials said.

Attorney General Gurbir Grewal said the attack was driven by hatred of Jews and law enforcement, and is being investigated as an act of domestic terrorism.

The two killers were armed with a variety of weapons, including an AR-15-style rifle and a shotgun that they were wielding when they stormed into the store in an attack that left the scene littered with several hundred shell casings, broken glass and a community in mourning. A pipe bomb was also found in a stolen U-Haul van.

“The outcome would have been far, far worse” if not for the Jersey City Police, Grewal said Thursday. Authorities noted that a Jewish school is next to the market, and a Catholic school is across the street.

The attackers killed three people in the store, in addition to a police officer at a cemetery about a mile away, before dying in an hours-long gun battle with police Tuesday afternoon, authorities said.

“The evidence points toward acts of hate. I can confirm that we’re investigating this matter as potential acts of domestic terrorism fuelled both by anti-Semitism and anti-law enforcement beliefs,” the attorney general said. He said social media posts, witness interviews and other evidence reflected the couple’s hatred of Jews and the police.

Grewal noted that after killing three people in the store, the couple concentrated their fire on police and did not shoot at others who happened to be on the streets.

Grewal said the attackers, David Anderson, 47, and Francine Graham, 50, had expressed interest in a fringe religious group called the Black Hebrew Israelites, whose members often rail against Jews and whites. But he said there was no evidence so far that they were members, and added that the two were believed to have acted alone.

The pair brought their cache of weapons in a U-Haul van they drove from Bay View Cemetery, where they shot and killed Jersey City Detective Joseph Seals, according to the attorney general.

The Tunnel2Towers organisation, formed after September 11 to support police officers killed in the line of duty, said Friday it would pay the mortgage of Seals, who left behind a wife and five children.

Director of Public Safety James Shea called Seals “the ultimate detective or officer we would point to tell young officers, ‘This is how you should behave.'” He said Friday that he doubted Seals would have been ambushed by the pair. Authorities haven’t disclosed why Seals was in the cemetery or details of the confrontation that led to his death.

Anderson fired away with the AR-15-style rifle as he entered the store, while Graham brought a 12-gauge shotgun into the shop. They also had handguns with a homemade silencer and a device to catch shell casings. In all, they had five guns — four recovered in the store, one in the van — in what Grewal called a “tremendous amount of firepower.”

Serial numbers from two of the weapons showed that Graham purchased them in Ohio in 2018, the attorney general said.

The victims killed in the store were: Mindel Ferencz, 31, who with her husband owned the grocery; 24-year-old Moshe Deutsch, a rabbinical student from Brooklyn who was shopping there; and store employee Douglas Miguel Rodriguez, 49. A fourth person in the store was shot and wounded but managed to escape, authorities said.

Members of New York’s ultra-Orthodox Jewish community gathered Wednesday night for funerals for Ferencz and Deutsch. Thousands of people, mostly men, followed Ferencz’s casket through the streets of Brooklyn, hugging and crying.

The bloodshed in the city of 270,000 people across the Hudson River from New York City spread fear through the Jewish community and weighed heavily on the minds of more than 300 people who attended a vigil Wednesday night at a synagogue about a mile from where the shootings took place.