The prosecution says six year old Wesley Mullins was killed by Lewis "Buck" Ballard to keep him quiet.
His defense argues the police arrested the wrong man and even point the finger at Mullin's grandfather.
At the time of Mullin's death, two years ago, both Ballard and Bobby Mullins, Wesley's grandfather, we're living together.
The prosecution says the boy would visit them every weekend.
During the opening arguments of Ballard's murder case, the Commonwealth's Attorney told the jury that Ballard had sexually assaulted the boy while his grandfather was asleep.
He says Ballard then killed Mullins to keep him quiet, claiming the child's skull was broken in 6 places and Wesley had been beaten to death, found in the garage at his Grandfather's home.
The Commonwealth says blood was found on the boots of Ballard and DNA was found on Mullin's body.
The defense says the Paris Police Department was in over it's head and didn't look at the possible suspects before arresting Ballard.
They say his Grandfather waited hours before calling police and looking for the boy who had gone missing.
They also claim the DNA evidence is inconclusive.
The first witness in this case will take the stand on Friday.