A grandmother on Thursday called for the release of police body camera footage from the incident last month when authorities say deputy city marshals in central Louisiana opened fire on a car, killing her 6-year-old grandson.

Cathy Mardis, 46, of Hattiesburg, Mississippi, spoke outside a courthouse in Marksville, Louisiana, where a grand jury was scheduled to meet to decide whether to indict the two officers.

"It's been pure hell. I can't explain what it's like to bury your 6-year-old grandchild," said Mardis.

Jeremy Mardis was killed and his father wounded during a Nov. 3 shooting in Marksville that sparked widespread outrage and the eventual arrest of two of the officers involved in the incident.

Police say Derrick Stafford, a full-time police lieutenant, and Norris Greenhouse Jr., a former police officer, were moonlighting as deputy city marshals when they fired at least 18 rounds at a car driven by Chris Few. The shooting severely wounded Few and killed Mardis. Stafford and Greenhouse were arrested on second-degree murder charges last month.

Cathy Mardis said she has not seen the tape and can only imagine what is on there but added: "I thank God the tape is there."

"I want justice for Jeremy. I want justice for Chris," she said. Their family is devastated by the death of the grandson, Mardis said. She said they had an open casket funeral for her grandson even though there were signs of trauma on his body.

She quoted the funeral director as saying, "Don't touch his head. It might fall back apart."

State Police Col. Mike Edmonson cited the tape when he announced the arrest of the two officers, calling it the most disturbing thing he's seen. But he gave no indication of what's on the video.

Last month, an attorney for Few told The Associated Press that video from another officer's body camera showed Few had his hands up inside the vehicle and didn't pose a threat when the officers opened fire. The judge hearing the case then swiftly imposed a gag order, keeping those involved from speaking to the media.

The grandmother was wearing a Teenage Mutant Ninja Turtles T-shirt, in honor of her grandson who loved the characters. Standing by her side was Samantha Few, the mother of Chris Few. But Samantha Few answered no questions from reporters, saying that she is subject to the gag order.

Cathy Mardis also spoke lovingly of her grandson. He was autistic and non-verbal but very bright, she said.

"He was the most loving child you could have met. He was always smiling and happy. He taught himself to read at three years old just from watching YouTube," she said. Jeremy Mardis has a younger sister who still cannot understand what happened, the grandmother said.

"She's still asking to see her brother every day," she said.