Those new charges, revealed Wednesday, include  domestic terrorism  and 13 other hate crime charges.

This is believed to be the first time a person in New York State has been charged with this domestic terrorism crime, which was created by a 2020 state law enacted after an anti-Semitic attack in Rockland County.

An Erie County grand jury indicted Payton S. Gendron on first-degree domestic terrorism motivated by hate, 10 counts of first-degree murder, 10 counts of second-degree murder as a hate crime, three counts of attempted second-degree murder as a hate crime and a weapons possession charge.

"In this case, there is overwhelming proof of the defendant's guilt," Assistant District Attorney John P. Feroleto told the judge, arguing that Gendron, 18, remain in custody without bail.

Feroleto said Gendron was caught at the scene with a gun in his hand. He also said Gendron had a camera on his person when he was caught and authorities have the video recording of what the camera captured during the attack.

Additionally, some of the charges carry significant prison terms upon conviction, Feroleto said. A person convicted of that domestic terrorism count is automatically sentenced to life in prison without parole. The first-degree murder charges also carry the possibility of life without parole.

Gendron, who drove to Buffalo from Broome County to commit the crime, the prosecutor said, has no ties to the community.

County Judge Susan Eagan ordered that Gendron remain held without bail.

Gendron's defense attorneys did not argue for his release, but reserved the right to request a change in bail status at a later date.

In his only audible words, Gendron said, "Yes, your honor," when asked by the judge if he understood he had a right to be present during the court proceedings. 

Ten people were killed and three others injured in the May 14 attack at the Tops Markets on Jefferson Avenue, the deadliest mass shooting this year in America until it was followed by another massacre 10 days later at an elementary school in Uvalde, Texas, in which the shooter killed 19 students and two teachers. Four people were killed in a mass shooting at a medical office building in Tulsa, Okla., on Wednesday afternoon.

Prosecutors have turned over to Gendron's defense attorneys video of statements made by Gendron that were captured on police body-worn cameras, Feroleto said during Thursday's arraignment.

Security at the courthouse was beefed up again, like for Gendron's prior court appearances. About 30 people watched the proceeding from the gallery.

Gendron, shackled at his ankles and wrists and dressed in orange jail garb, was escorted into and out of the courtroom by more than a half-dozen officers. Other officers were stationed around the courtroom.

In a news conference after the arraignment, District Attorney John Flynn credited law enforcement agencies that have played a part in the investigation to this point. He thanked FBI Director Christopher Wray for sending 16 victim advocates from the agency to Buffalo to help support victims' families.

Police and prosecutors initially charged Gendron with one count of first-degree murder in Buffalo City Court. That charge covered the 10 killings. Gendron may also face federal charges.

Gendron was scheduled to return to county court on July 7.