The man and woman who killed four people in Jersey City last month during a rampage at a kosher supermarket had planned “greater acts of mayhem” on Jewish communities, authorities said Monday. David Anderson, 47, and Francine Graham, 50, allegedly prepared for months before the deadly Dec. 10 attack, which also killed a Jersey City police detective. State and federal authorities also said Monday that the bomb found in the van of the attackers could have killed people up to five football fields away, and there was sufficient material in the van to make a second bomb. New Jersey Attorney General Gurbir S. Grewal said that investigators believe the two attackers were “fueled both by anti-Semitism and anti-law enforcement beliefs” and they are treating the shooting as an act of domestic terrorism.

Authorities previously said that the assailants were fueled by Black Hebrew Israelite ideology and that they likely would have taken more lives if they hadn’t encountered by chance Jersey City Det. Joseph Seals, who was killed in the Bayview Cemetery. New Jersey U.S. Attorney Craig Carpenito said on Monday that video footage from the kosher supermarket captured Anderson saying, “They stole our heritage, they stole our birthright, and they hired these guys to stop us.”