Investigators have found ties between the two killers who stormed a kosher market in Jersey City this week and the Black Hebrew Israelites, after originally saying the attack appeared random.

The attackers have been identified as 47-year-old David Anderson, and his 50-year-old girlfriend Francine Graham. Graham is a four-year veteran of the Army reserve, and previously spent more than a year in jail in the state for pleading guilty to weapons charges over a decade ago.

The connection was determined after officials found that one of the shooters apparently posted anti-semitic messages online, and was a follower of that fringe movement that expresses hostility towards Jews and white people.

But, authorities have warned they are still working to determine the motive for the attack, and whether it was inspired by that Black Hebrew Israelites connection.

“The why and the ideology and the motivation — that’s what we’re investigating,” said New Jersey attorney general Gurbir Grewal on Wednesday, noting that they are still looking for others who may have been involved in the attack.

The shooting on Tuesday left a police officer dead alongside three civilians, after the two attackers opened fire at a kosher market in Jersey City with what have been reported as long rifles. The shooting drew national media attention, running on several major cable news channels in real time. Both suspects were also killed.

During the investigation that followed, a series of leads have emerged. For instance, authorities have said they found a rambling religious manifesto inside of the suspect’s rental van.

Authorities also say the attackers have become prime suspects in the separate murder of a 34-year-old livery driver, whose body was found stuffed into the trunk of a Lincoln Town Car in nearby Bayonne.

Black Hebrew Israelites are groups of African Americans who belive they are the descendants of ancient Israelites, and adhere to varying degrees to practices of Christianity and Judaism.

The fringe elements of the group have been identified previously, in 2008, by the Southern Poverty Law Centre as being a black supremacist group. The extreme elements of the group view white people as "inherently evil", and that "they are 'blue-eyed devils.'" And, they view Catholics and Jews as practising a "gutter religion" that preys on black people.