JERSEY CITY, N.J. (CBSNewYork) — It has been one year since a mass shooting in Jersey City that left a police detective and three civilians dead.

Det. Joseph Seals was shot and killed at Bayview Cemetery, where a remembrance was held Thursday.

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Fellow officers, officials and family members gathered to reflect on the life of the 39-year-old married father of five and 13-year veteran of the force.

“It seems like it was yesterday, it seems like it was days ago that we were in the middle of a gun battle,” Jersey City Police Chief Michael Kelly said at the ceremony. “He was an elite cop, he was an elite radio car cop, he was an elite street cop.”

“He chose to meet an informant here in the cemetery by himself. He chose to because he thought it would be beneficial,” said Jersey City Mayor Steven Fulop. “He chose to walk over to a vehicle that he recognized that could have been involved in something else throughout the city. He chose to put himself in harm’s way because he thought that would be something that keeps other people safe.”

“Devotion, humility, if you  want to be an elite cop, there’s your model,” Kelly said.

WATCH CEREMONY: Jersey City Marks 1 Year Since Deadly Shootout  

Seals was shot by suspects Francine Graham and David Anderson, who then drove a stolen U-Haul van outfitted with ballistic panels and packed with a pipe bomb and guns to the JC Kosher Supermarket nearby and entered with rifles in hand.

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The two engaged in a shootout with police for hours, sparking a massive response by law enforcement from surrounding towns and cities, including the NYPD.

Police eventually battered down the storefront with an armored vehicle. Inside, they found three innocent people in the store dead, along with Anderson and Graham.

The massacre was investigated as domestic terrorism. Officials said it was fueled by both Antisemitism and anti-law enforcement beliefs.

“Many, many, many military-style rifles, so they had big plans for major damage, and we’re really proud of what the police department did that day, averting that,” Fulop told CBS2’s Alice Gainer.

A mural has been painted at the former kosher grocery store in Jersey City where three people were killed on Dec. 10, 2019. (Credit: CBS2)

A mural with three blue roses for the three victims killed is now painted where the JC Kosher Supermarket was located. The store reopened about a block and a half away.

PHOTOS: Scenes From Jersey City’s Deadly Shootout

So much was lost that day. Thursday was a day to remember.

“Today serves as a reminder of the sacrifice and the commitment that law enforcement make,” Fulop said.

“We didn’t have the chance all year long to talk about Joe Seals, and we’re going to talk about him today. We’re going to show out today for his wife Laura, his five children, his mother Debbie. We’re here today, and we’re here forever,” Kelly added.

As for the lessons learned since that day, police maintain that things went according to training. They have no updates on the investigation, but say it remains open.

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