KNOXVILLE, Tenn. (WVLT) -- Prosecutors have used Lemaricus Davidson's ex-girlfriend to link him to the murders of a Knox County couple he's now on trial for killing.

Davidson has pleaded not guilty to carjacking, kidnapping, raping and killing Channon Christian, 21, and Christopher Newsom, 23, in January 2007.

He's the second of four suspects going to trial for the crimes.

Davidson's ex-girlfriend Daphne Sutton is not new to the witness stand. She's testified in two other trials related to these the crimes, but the questioning and testimony were never quite like they were in the third day of Davidson's trial.

Sutton testified that she met Davidson through a friend. She was living at the Chipman Street house where the crimes allegedly occurred, but testified she moved out just before police say Christian and Newsom were kept captive there, then killed.

Sutton said Davidson called her while she was staying with friends.

"He told me he had clothes for me to come and get." Sutton said. "He said to wait 30 minutes before we came over."

She didn't, and when she arrived, Sutton testified, Davidson blocked her from the kitchen.

"That's when he grabbed me and said, 'this is my house.' "

Police found Christian's body stuffed in a trashcan in the kitchen a few days later.

As for the clothes Sutton was given, they've been identified as belonging to Christian.

The defense quickly criticized Sutton's credibility, quizzing her about what she told police.

"You made some statements and they told you you were lying," the defense asked.

"Yes," she replied.

"You decided you would cooperate with authorities because you were worried you'd be arrested."

"Yes."

"Just like you're afraid of being arrested in the case Ms. Fitzgerald just asked you about."

The defense also continued trying to connect the victims to Davidson.

Defense attorney Doug Trant asked, "While you were dating Mr. Davidson, do you remember being in a liquor store parking lot?"

"Yes," she responded.

"And do you remember being at liquor store? He was taking to a white woman in a 4Runner."

"Yes."

Channon Christian drove a Toyota 4Runner, but Sutton later told prosecutors that was an older model 4Runner, and different in color from Christian's.

The couple's parents say their kids shouldn't be put on trial.

Christopher Newsom's father, Hugh Newsom, said, "My son was good son. I tell you, I'd give everything I have to have him back."

Channon Christian's mother, Deena Christian, said, "I just want them to know, that she's a better person than I am."

The defense's implications of drug use by their kids and questioning what really happened when they were carjacked has taken a toll on the Christian and Newsom families.

They say they shouldn't have to defend their kids.

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KNOXVILLE, Tenn. (WVLT) -- Today marks the third day of Lemaricus Davidson's trial for allegedly carjacking, kidnapping, raping and murdering Channon Christian, 21, and Christopher Newsom, 23, in January 2007.

Testimony is set to begin at 9 a.m.

Prosecutors plan to call Davidson's ex-girlfriend, Daphne Sutton, to the stand.

It will be the first time Sutton comes face-to-face with Davidson to testify.

Sutton's previously testified at Eric Boyd's trial in April 2008 and Davidson's half-brother, Letalvis Cobbin's trial this past August.

Boyd was convicted as an accessory after the fact and is serving 18 years in prison. A jury convicted Cobbins of first-degree murder in Channon Christian's death and sentenced Cobbins to life in prison without parole.

Unlike Davidson's half brother, Letalvis Cobbins, who has already had his day in court, Davidson requested a Knox County Jury.

Volunteer TV's Mike McCarthy is at the courthouse, and he'll be providing updates all day on Volunteer TV News and on VolunteerTV.com. You can also follow his updates on Twitter. Just follow @WVLT.