Defense attorneys for Brandy Nicole Williams rested their case Friday without her taking the witness stand.
The trial is scheduled to resume Monday in Oxford with a state rebuttal witness and closing arguments.
Williams faces life in prison without the possibility of parole if she's convicted of capital murder. Her then-boyfriend, Christopher Lee Baxter, was convicted of the same charge in May.
Williams is accused of driving the pickup truck that struck and killed Welford as she and Baxter fled from authorities on July 21, 2010. Baxter was wanted on an arrest warrant issued after he missed a sentencing date for drug convictions.
A defense lawyer has said Williams didn't intend to kill the sheriff.
Three defense witnesses testified Friday about Williams' character and her mental state before and after meeting Baxter.
Renee Vischer, who was Williams' boss from 2008 to 2010, said Williams was "very kind-hearted, dedicated, loving, sweet" but changed after she began dating Baxter.
"I would try to get a hold of her, try to get her to come by," Vischer said, according to a SunHerald report. "She withdrew. He was draining her."
Rita Butler, Williams' neighbor, said Williams had a tough home life due to an alcoholic mother. Her mother's alcohol-fueled fits of rage were "a pretty regular thing," Butler said, according to the Mississippi Press.
Butler also testified she suspected Baxter was abusing Williams, but she never witnessed it firsthand.