Carolyn Jones, 48, was charged with first-degree murder in the death of her granddaughter Royalty Marie Floyd.
Officials said Jones stabbed Royalty before shoving her in the oven.
The cause of death was both the stabbing and the burning, the Bolivar County Coroner’s Office told WMC.
The disclosure came a day after the community in Shaw held a vigil for the toddler.
“The love, support, the sharing that we do there in Shaw, we always look out for each other and this was really shocking, and it hurt,” said Shaw Mayor Everett Stanton to the crowd.
A local law enforcement called what happened “one of the most horrible things I’ve seen.”
“I’ve been doing law enforcement for 25 or 26 years now,” Bolivar County Sheriff Kelvin Williams Sr. said. “This is one of the most horrible things I’ve seen in doing law enforcement. The hardest part … is to see a child victim.”
Jones appeared in court for the first time on Oct. 16. A judge set her bail at $500,000 and she remained in jail.
Sheriff’s deputies said Royalty lived with Jones while her mother lived elsewhere. Veronica Jones, the girl’s mother, said in a statement on her Facebook that she missed her daughter.
“Royalty Marie Floyd was the best thing that ever happened to me,” Jones said. “She’s my one and only daughter. My first love. The hardest thing that I ever had to go through in my life. My heart has been ripped from my chest.”
— Kelli Cook (@TVKelliC) October 22, 2018
She said her mother always treated her granddaughter well. “She always treated Royalty like royalty,” she said. “My mom was obviously not herself,” she said. The toddler was found dead on Oct. 15 in Shaw, a town of about 2,000 people about 100 miles northwest of Jackson.
Spokesman Warren Strain at the Mississippi Department of Public Safety said investigators weren’t sure why Jones killed the little girl. “That’s hard to say,” Williams said. “We don’t know.”
Jones also shared a link to a GoFundMe page where she’s raising money for Royalty’s funeral. It’s raised over $4,000 so far.
The Associated Press contributed to this report.