TWIN FALLS, Idaho -- An audio tape from a 2003 murder investigation was played in a Twin Falls courtroom Wednesday.
That recording could be a key factor in whether or not an Idaho woman convicted of killing her parents gets a new trial.
Sarah Johnson was just 16 at the time of her parents death in Blaine County. The now 23-year-old is seeking a retrial.
Johnson's attorney Christopher Simms broke down that gruesome crime.
Blaine County Sheriff Walt Femling took the stand and defended the investigation into the murders of Diane and Alan Johnson.
"There was literally blood from the ceilings, to the walls to all over the carpet, it was just a very, very gruesome scene," said Femling.
Femling recalled a shocking scene as he investigated the home of the Johnson family seven years ago.
"As I entered the master bedroom, as I stopped and I looked to my left, which was later identified as Sarah's bedroom, I could see that we had blood splatter into that bedroom as well," said Femling.
The sheriff was asked if he was quick to pin Johnson as the murderer.
Femling said from the crime scene, he could quickly tell the shooter was familiar with the Johnson's home, eventually coming to the conclusion Johnson pulled the trigger.
"The crime scene will tell you what happened, the crime scene will tell you who did it it. It just takes some time to get there," said Sheriff Femling.
Simms questioned Femling about the thoroughness of his investigation, claiming that key pieces of evidence were possibly overlooked. As part of his defense strategy, Simms played a two-hour recording in court of the first Idaho State Police officer to arrive on scene.
"We've got a body. One body in here."
The audio recording goes onto to recount the investigation as it unfolded that morning.
"It was a rainstorm of blood inside the bedroom, and Sarah didn't have any blood on her," said Simms. "She couldn't have done it. My question to you is, given the theory of the case, then and the days leading up to the indictment, were you at all troubled by the fact that Sarah didn't have any blood on her, yet she was being indicted as the shooter?"
"No, I didn't have any trouble with that at all," responded Femling.
Simms then questioned Femling about Sarah's involvement with Bruno Santos.
Santos, an illegal immigrant, was dating Johnson at the time of the murders.
Simms questioned Femling as to how much his investigators looked into Santos as a possible suspect.
"Did you ever rule in your mind, or decide in your mind, that you had ruled out the possibility that anyone else participated in this crime?" asked Simms.
"Yes, I ruled that out. I believe solely that Sarah Johnson acted alone in killing Alan and Diane," said Femling.
Femling also explained in court how he knew Sarah personally. He admitted that clouded his view and never believed a teenage girl could commit a crime like this. But he said the evidence from the crime scene, and DNA evidence from a bloody bathrobe led him to Sarah Johnson.
The hearing is scheduled to go through Friday.
Johnson is currently serving two life sentences without the possibility of parole.