What to Know One detective and three civilians were killed during a targeted shootout and standoff at a Jersey City kosher market last month

Two suspects, David Anderson and Francine Graham, were found dead inside the market; NJ's top prosecutor said their motivation was hate-fueled domestic terror

Investigators said Monday that a bomb found in their van could have killed or maimed people as far as five football fields away

The U.S. attorney in New Jersey and the head of the local FBI said Monday that the bomb found in the van of alleged domestic terrorists Francine Graham and David Anderson could have killed or maimed people up to five football fields away.

They also said there was enough material in the van to make a second bomb.

Four innocent people, including a veteran Jersey City police detective and father of five, died in the hail of prolonged gunfire. Most of the victims were found inside the JC Kosher Supermarket on Martin Luther King Boulevard during what officials have described as a hate-fueled terror spree on Dec. 10.

The officer who died, Det. Joseph Seals, was killed at a cemetery, where authorities said he had gone to meet with a man to talk about the return of a vehicle impounded by police. Details will never be definitive, authoritis said, but investigators believe Seals approached the suspects' van because cops were looking for it in connection with the murder of a livery driver the prior weekend. Cops are still looking into a possible connection between the driver's death and the terror that was unleashed in Jersey City on Dec. 10.

Seals' death first brought law enforcement near the scene of what would become a horrific bloodbath, leaving schools with bullet-riddled windows and the neighborhood locked down.

U.S. Attorney Craig Carpenito said of Seals, "We believe he threw off a broader plan," and that his actions "probably saved dozens if not more lives."

Francine Graham had no known criminal record, and law enforcement officials haven’t found any radical or hateful content on her social media pages. The same cannot be said for David Anderson, who had a previous gun arrest and was a member of the Black Hebrew Israelites. NBC New York’s Jonathan Dienst reports.

Authorities could not detail what that plan would have been, other than to say that Graham and Anderson had done research on a Jewish community center in Bayonne. They did confirm earlier preliminary suspicions that the shootout was a bias crime against Jews and against the law enforcement community. The shooters were found dead when the gunfire ended.

Authorities do not believe a Yeshiva next door to the kosher supermarket was targeted, but said they had cased the grocery store multiple times, including the morning of the attack. Carpenito also confirmed a News 4 report that several days before the shooting, a Jewish man driving near Newark Airport had been shot at; ballistics show two of the shots that hit the man's car came from one of Anderson and Graham's guns. The livery driver who died the weekend before the attack was shot with the same weapon that fired on the vehicle near the airport, authorities said.

The NJ attorney general called the Jersey City shootout that killed 4 people a hate-filled domestic terror attack, as more details surfaced about how it all went down. NBC New York’s Brian Thompson reports.

Carpenito also confirmed an earlier report from News 4 that both supsects had handcuff keys in their underwear. He said there was no evidence of co-conspirators and that the two went to Ohio for target practice not long before the attack.

The FBI has found a white Ford van with New Jersey license plates that it was searching for in connection with its investigation into this week's deadly shooting attack at a Jersey City kosher supermarket. Anjali Hemphill reports.

Officials have said they believe the two attackers identified themselves in the past as Black Hebrew Israelites, a movement whose members have been known to rail against white people and Jews. Authorities have said they have not established a formal link between the pair and the group.

Investigators also have found social media postings from Anderson that were anti-police and had anti-Jewish elements, law enforcement sources with knowledge of the case previously told News 4.

Five firearms to date have been linked to the duo. Four — an AR-15 style weapon, a shotgun, and semiautomatic firearms, including a Glock — were recovered from inside the kosher market. A fifth — a weapon with a homemade silencer and a homemade device to catch shell casings — was discovered in the U-Haul they drove to the market. That van was outfitted with ballistic panels; it also had the bomb inside.

Investigators have been able to track two of the five weapons thus far via their serial numbers. Both, Grewal said, were purchased by Graham at separate gun shops in Ohio in the spring of 2018.

The investigation into the shootout and the suspects is being led by federal authorities and conducted by a joint coalition of law enforcement entities. That investigation is ongoing, Carpenito said Monday.

It was a day of healing for people in and around Jersey City on Sunday as harrowing stories of survival were shared by survivors of Tuesday's shooting. Ken Buffa reports.