DeKalb County police believe Gregory Williams forced his way into his 78-year-old grandmother’s bedroom, attacked her with a “Rambo-style” knife and disposed of her body with her car, warrants released Monday say.

The documents say blood was in the trunk of Millicent Williams’ car when her grandson was found driving it last week. There was also a layer of CD cases, with some cracked from apparent pressure.

The grandson allegedly told police he would reveal the location of the body if they got him a lawyer, but it isn’t clear if the deal has worked out. Police still hadn’t found the grandmother’s body Monday, but the warrants say they know she is dead because no one could survive losing the amount of blood found in the car and her home.

The warrants allege the assault happened at her Brookgreen Point home outside Decatur sometime between last Sunday and Thursday.

Gregory Williams, left, a suspect in the disappearance of his grandmother, right, is in custody on felony murder, kidnapping and theft charges. Millicent Williams is still missing.
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Court and police records suggest a long, troubled relationship between the grandmother and grandson. She said he suffered from PTSD after service in the Army and refused to take his medicine.

Though his grandmother believed he'd served in Iraq, Gregory Williams was never deployed, the Army said.

Twice she took out protective orders against him, the last expiring at the end of 2015.

RELATED: Missing grandmother had previously feared for her life

RELATED: Grandson charged with kidnapping, assault

Gregory Williams had been in jail since Thursday, when he was found in his grandmother’s car. He was arrested in a Kroger parking lot.

In addition to felony murder, he’s charged with kidnapping, aggravated assault and theft by taking.

The search for the grandmother’s body is expected to resume Monday afternoon, police said.

Return to ajc.com for updates on this developing story.

A man is accused of attacking his grandmother and leaving her body in an unknown location.