JONESBOROUGH, Tenn. -

Update: Click here for coverage of day two of the trial.

A jury has been selected and the trial is underway for a man accused of killing a Mountain City couple.

Marvin "Buddy" Potter is charged with two counts of first degree murder and one count of felony murder.

There is a lot of emotion inside the courtroom in Jonesborough as family members of the victims are listening to both sides, and are hoping to have some answers.

Both sides gave opening statements and had different theories on what they believed happened on Monday.

A 911 call was played for jury members Monday by the defense during the opening statements of Marvin Potter's trial. "Is his chest throbbing where you can see?" asked the 911 operator. "No, no, there is no pulse on him. I know there is no pulse on him," the caller replied.

The call was placed on the morning of January 31, 2012, when the bodies of Billie Jean Hayworth and Billy Payne, Jr. were found in Johnson County.

"We don't think the facts that you're going to hear from this witness stand is going to back up their theory at all," defense attorney Randy Fallin said. "We have a different theory and a different shooter."

But the prosecutor Dennis Brooks has a different opinion on what happened. "We are going to show you that you are in the [presence[ of someone trained and cold-blooded enough to do that kind of crime, at least he thinks he is," Brooks told the jury.

Police say Potter got angry at the couple after they de-friended his adult daughter Jenelle Potter on Facebook. "An enemy of Jenelle Potter is an enemy of Marvin Potter," Brooks said. "You don't de-friend her or act like you don't want to be her friend without something going on."

But the defense claims the group met and made up a month before the shootings took place. "Before that meeting they were concerned with all the problems going on," Fallin told the jury. "After that meeting there wasn't another mention of problems between the Potters and him."

Jury members were shown pictures of the bodies, how police found them, and listened to testimony from a Tennessee Bureau of Investigation agent that worked the scene. They also read emails between the Potters.

The defense claims Marvin Potter never used e-mail or a computer because he didn't know how.

The trial is expected to last a week. The prosecution will continue to call witnesses on Tuesday.