Police did not release the woman's identity on Monday because they are still trying to contact her relatives.
Police initially responded to the home just before midnight for a report of a cutting and an attempted suicide, according to charging documents police filed in court. Upon arrival, officers say the victim suffered from stab wounds to her torso and back. She was pronounced dead at an area hospital.
Police said they found an 8-inch knife in the kitchen sink in the home and blood stains on a pink and white comforter on an inflatable mattress in the living room. Police said Thornsberry was outside on his cellphone after the stabbing and was overheard using the word "kill," charging documents say.
Detectives questioned him, and he told police that the victim was drinking and got into a physical altercation with him, police said. He said he left the home and returned to find her holding the knife police had found, investigators said. Thornsberry told police that she sustained the wounds during a struggle where he tried to get the knife out of her hand, police said.
But the detectives noted in their report that he did not call 911 after the incident but had a friend call 40 minutes after the victim had sustained the wounds. Police also said he admitted to washing the knife.
An autopsy came back saying the victim had died as a result of "homicide" or at the hands of another person, and detectives arrested Thornsberry.
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