KINGSTON, Tenn. (WVLT) -- The retrial begins today for a Roane County man charged with the murder of a county sheriff's deputy and his ride along partner back in 2006.

Leon Houston is charged with the murder of Deputy Bill Jones and Mike Brown, killed in Jones' police cruiser outside Houston's home.

On the witness stand, Brown's mother Patricia told jurors, "When he went out the door I told him, I said I love you. He said, you too. I said be careful."

Patricia Brown was the first to take the stand in the retrial of Leon Houston.

Houston is charged with killing Brown's son Mike, and Deputy Bill Jones on May 11, 2006 while they were in Jones' police cruiser attempting to serve a warrant on Houston's brother Rocky.

Special Prosecutor Ken Irvine told jurors, "Suddenly he notices that everyone has jumped to their feet and Rocky explains, "It's on now."

In opening statements, prosecutors say it was a Houston ambush on the deputy and his ride along partner.

That Rocky was engaged in a gun battle with the pair while Leon helped out also shooting at the deputies.

"What's significant about what he's doing is he's keeping the passenger inside the car. The passenger can't get out. They're caught in a crossfire," says Irvine.

Leon's attorney Jim Logan told jurors, "My client never killed anybody. Medical proof will show you."

Logan says none of the fatal shots to either victim was fired by his client Leon Houston, questioning who fired first.

"In fact, you may well conclude that the first person that got shot is Rocky Joe Houston," says Logan.

The Houston's were known to law enforcement, and law enforcement to the Houstons.

One deputy testified she had a conversation with Jones at the start of his shift.

Melissa Heidinger who served as a deputy with Jones that day told jurors, "He just stated that Rocky Had driven by his house prior that day, earlier that day."

Later an off duty deputy told Jones he saw Houston at his home and there were warrants for his arrest.

That same deputy later came to the scene and found Brown and Jones.

Roane County Sheriff's Deputy Guy McGuckin testified, "He was slumped over toward the passengers seat. Was he alive or dead? He was dead."

Rocky Houston's first trial ended in a mistrial as did Leon's.

Testimony is expected to continue Friday morning.