Payton Gendron, the 18-year-old suspect, alleged to have killed 10 people at an Erie County supermarket in Buffalo, has been indicted by a grand jury on charges connected to the shooting after he appeared in court on Thursday, as Washington Post reports. Gendron has pleaded not guilty.

According to authorities, Gendron — who is believed to be a white supremacist — targeted the Tops supermarket in the predominantly Black neighborhood on Saturday. Authorities claim the killings were racially motivated due to Gendron’s alleged beliefs in a “great replacement theory” — a baseless conspiracy theory touted by right-wing media and the far-right fringes that white people are facing extinction and are being “replaced” by immigrants and people of color.

At the hearing on Thursday, which was attended by some of the victims’ families, prosecutor Gary Hackbush informed Buffalo City Court Chief Judge Craig D. Hannah that an Erie County grand jury had voted for an indictment against Gendron the day before. The charges have not been made public. Gendron remains in custody and is being held without bail.

During the hearing, a person in the courtroom yelled, “Payton, you are a coward,” at the suspect as he was being taken to a holding area, according to the Washington Post.

Authorities said Gendron had traveled more than 200 miles from Conklin, New York, to the Tops Supermarket with a rifle, opened fire, and killed 10 people. He had allegedly published a 180-page manifesto where he pushes the great replacement theory. The U.S. Justice Department is also investigating whether to charge Gendron with a hate crime. The killings marked the 198th mass shooting in the United States and the deadliest one to date of 2022.

Gendron is expected to return to court on June 9 for arraignment on the indictment.