A Jersey City Police Department detective had also been shot and killed by the assailants at a nearby cemetery just before the grocery store attack.

[5][6][7] Anderson, who identified as a Black Hebrew Israelite, had a history of posting antisemitic and anti-law enforcement messages on social media; Attorney General of New Jersey Gurbir Grewal stated that evidence indicated that the attacks were acts of hate and domestic terrorism which were fueled by antisemitism and anti-police sentiment.

[12][17][16] His body was discovered by a bystander and reported at 12:38 p.m.[1][18] The suspects immediately fled in the stolen van and drove about one mile to a kosher grocery store, the JC Kosher Supermarket in the Greenville section of Jersey City, and they opened fire immediately after they exited the vehicle; the assault was exclusively directed towards the store, and bystanders in the street were ignored as a result.

[36] Anderson and Graham were suspects in the murder of Uber driver Michael Rumberger in Bayonne the weekend prior to the attack, on December 7.

[40][41][42] In January 2020, officials announced that evidence showed that Anderson and Graham had planned much larger attacks against both the Jewish community and law enforcement which could have resulted in dozens of casualties or more, but that the intervention by Detective Seals had disrupted these.

[16][44] Anderson identified as a Black Hebrew Israelite, a movement which has no connection to mainstream Judaism and parts of which are listed as hate groups by the Southern Poverty Law Center, and social media posts by Anderson, sometimes under the alias "Dawad Maccabee," invoked tenets of Black Israelite philosophy;[45][44][5][8] these included affirmations of the Khazar Myth, references to Jews as Nazis, the claim that Jews were "imposters who inhabited synagogues of Satan," and assertions that the police were under the control of Jews.

[44][5][25] A former neighbor recalled Anderson spending considerable time listening to what the neighbor believed were sermons by Louis Farrakhan, but other posts by Anderson accused Farrakhan of being a "rat" and a "con" for posing in photos with the members of the Neturei Karta, an extremist Orthodox Jewish sect.

[55] Governor of New Jersey Phil Murphy expressed his condolences, his thoughts and prayers for police, residents, and school children, and praise for the slain detective in a series of tweets.

[citation needed] On Twitter, Rep. Rashida Tlaib (D-Mich.) wrongly accused "white supremacists" of being responsible for the assault, deleting her tweet soon after.

[58] Mayor Fulop said a trustee of the Jersey City Board of Education, Joan Terrell-Paige, should resign due to a Facebook message she posted after the shooting, in which she said black residents were "threatened, intimidated and harassed" by "brutes of the jewish community" [sic].

[66] Fulop said that analysis of the assailants' computers showed that they likely intended to do more harm, that the yeshiva was the probable target of the attack, and that they "moved more quickly" with their plans because of their encounter with Detective Seals.

The most common tactics in domestic extremist attacks include easily obtainable weapons, such as knives, small arms, and vehicles.

[69] On October 7, 2020, a pawn shop dealer in Keyport, New Jersey whose phone number was found in Anderson's pocket pleaded guilty to the charge of being a felon in possession of a weapon.

[70] In November 2020, a grand jury determined that the actions of 12 Jersey City officers and one Newark police detective who shot Anderson and Graham were justified and that no charges were warranted against them.