Mardis was sitting in the passenger seat of his father's vehicle when the marshals allegedly fired 18 rounds

A Louisiana grand jury indicted two marshals on second-degree murder charges for allegedly fatally shooting a 6-year-old autistic boy who was sitting in the passenger seat of his father’s vehicle during a police chase, PEOPLE confirms.

Marksville, Louisiana, city marshals Derrick Stafford, 32, and Norris Greenhouse Jr., 23, allegedly opened fire on a car driven by Jeremy Mardis’ father, Christopher Few, during an incident that began when Few allegedly fled the marshals who were trying to serve him a warrant. The cops allegedly fired at least 18 rounds between them, according to multiple reports, killing Mardis and injuring Few, who subsequently spent a week in the hospital.

Get push notifications with news, features and more.

Stafford and Greenhouse were arrested in early November after an investigation by the Louisiana State Police.

“Today’s indictments will allow the State to move forward in the process of seeking justice for Jeremy Mardis and to hold accountable those who are responsible for his death, Louisiana Attorney General James D. “Buddy” Caldwell said in a statement.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Cathy Mardis, Jeremy’s grandmother, told reporters outside the courthouse, “It’s been pure hell. I can’t explain what it’s like to bury your 6-year-old grandchild.”

After the arrests of Stafford and Greenhouse, Louisiana State Police superintendent Col. Michael Edmonson told reporters that body camera footage helped lead to the arrests. He did not reveal what was on the footage, but he said, “I can tell you, as a father, it was one of the most disturbing things I’ve witnessed.”

A state police spokesperson tells PEOPLE a gag order has been issued by a judge and that the state police will not give out further information.

Stafford and Caldwell were accused earlier this year in a civil rights lawsuit of using excessive force on a man at an Independence Day event, PEOPLE confirms.

Greenhouse is currently free on bail and Stafford is being held at the Rapides Parish Jail in lieu of $1 million bail, according to The Advocate.