Twenty years after a young Tulsa mother was convicted of murdering her 3-month-old son, her attorney is shedding light on evidence that could prove her innocence.
Police have a taped confession of Michelle Murphy, saying she leaned over her baby with a knife and accidentally killed him.
Her attorney says that was a forced confession, and if her original lawyers would have done their homework, he believes they would have discovered someone else's blood at the scene of the murder.
On September 12, 1994, her attorney said 17-year-old Michelle Murphy found her three month old son laying in a pool of blood inside her Tulsa apartment, his throat slashed.
Murphy was arrested for her baby's murder and sentenced to life without parole a year later.
"There were a lot of mistakes made unfortunately," said Murphy's attorney, Richard O'Carroll.
Almost 20 years later, Murphy's new attorney has filed a petition, which he says proves his client is innocent.
"The trial lawyer never introduced her blood type, which would have exonerated her in front of the jury," O'Carroll said.
Court documents show police took samples of blood that were "very red and appeared fresh" from the curtains, from under the baby, from the floor nearby and from the front door.
All of the blood matched the baby's type, except the blood found on the floor and the blood on the door. Those samples were Type AB.
"The defense lawyer did never introduce into evidence the fact that Michelle was Type A, so the prosecutor was able to infer that the AB blood was hers," O'Carroll said.
If Murphy and her baby are not type AB, then who could the AB blood belong to?
O'Carroll believes it is the prosecution's star witness, William Lee, who committed suicide after the preliminary hearing and before the case went to trial.
"He was the kind of kid who would cut heads off cats and hang them on porches. He really was disturbed," O'Carroll said.
Lee, who was 14 at the time of the murder, lived at Murphy's apartment complex. O'Carroll said Lee had a crush on Murphy.
According to court records, Lee called 911 during the early morning hours on the day of the murder to report a "domestic situation" at Murphy's apartment.
When police came to check out the scene, the only thing unusual they found was a chair propped up against the screen door.
"We're going to test his blood. If his blood is at the scene, I think it's over and it will be dismissed," O'Carroll said.
Lee's blood was collected after his suicide. A Tulsa County Judge wants Murphy and Lee's blood tested and compared to the blood at the scene.
Tulsa County District Attorney Tim Harris said his office supports the judge's decision to collect the DNA samples.