Inset: Christopher Medula (Hamilton County Sheriff's Office). Background: A camper burning in Hamilton County, Tenn., where Christopher Medula allegedly set his grandmother on fire (WTVC/YouTube).

A grandmother in Tennessee was set on fire by her own grandson, with the woman telling responding cops between labored breaths, "Chris did it. He poured gas on me. He's lost it," according to police.

The grandma was hospitalized with burns over 70% of her body and her next of kin has removed her from life support.

Christopher Medula, 39, later admitted to "dousing gas on the victim" and setting her ablaze with a "Bic style lighter" inside a camper in Hamilton County, according to an arrest affidavit obtained by Law&Crime on Wednesday. The alleged arson attack happened Tuesday afternoon.

"I poured gas on her," Medula told cops after being taken into custody, according to the affidavit. "I had to do it," he allegedly said. "She was evil. She raped me."

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A neighbor who witnessed the aftermath told police he saw Medula exit the camper as it caught on fire and his grandmother stumbled out after being "burned badly," according to the affidavit. Medula allegedly told cops he was "holding the door to her camper shut so she could not escape out of the camper" before the neighbor pulled up with a gun and got Medula to get on the ground after yelling at him.

"She's the devil," the neighbor recalled Medula saying, according to the affidavit. "I'm Jesus," Medula allegedly told him.

When first responders arrived at the scene, they found the grandmother lying in a driveway with her clothes "completely burned away" and third-degree burns covering her body. A neighbor had placed a blanket over her as she struggled to breathe and spoke to police.

"[The grandmother] was able to give deputies a statement, recorded on body worn camera … between her labored breaths," the affidavit says.

Police found the "cigarette lighter" that Medula is accused of using to light his grandmother on fire inside his pocket. He was charged with attempted first-degree murder, aggravated assault and aggravated arson for the alleged fire attack. He was being held at the Hamilton County Jail on a $1 million bond Wednesday with his next court appearance scheduled for Nov. 17.