TULSA, Oklahoma - A woman who was freed from prison after being sentenced to life for slitting her 3-month-old son's throat has filed a lawsuit for her wrongful conviction.

Michelle Murphy’s lawsuit says an officer at the time coerced a confession from her, planted evidence and that there was faulty and false blood comparisons.

The Tulsa Police Department, former Tulsa County District Attorney, Tim Harris and a number of former police officers are named in the suit.

Some of the allegations include:

  1. Ms. Murphy’s wrongful arrest, detention, prosecution, conviction, and imprisonment were the result of egregious misconduct by law enforcement officers, forensic analysts and their supervisors, acting individually and in concert to use any means necessary to obtain a conviction;
  2. Detective Mike Cook coerced a confession from the seventeen (17) year-old Ms. Murphy which had no basis in reality and Cook knowingly used this false evidence to support a probable cause arrest affidavit;
  3. Det. Cook prompted and threatened Ms. Murphy into stating she was in a “dream” and she “accidentally fell” and, if Cook is credited, she accidentally cut through the bone, grizzle and sinew of her infant son’s neck;
  4. At the end of the day, TPD was stuck with an implausible statement and a misleading new release to the media that Ms. Murphy was a murderess who had “confessed”;
  5. Faced with this reality, acting individually and in concert, the defendants then intentionally planted evidence and fabricated false inculpatory evidence against Ms. Murphy, irreparably and unconstitutionally tainting her criminal trial by distorting the other evidence presented against her – faulty and false blood comparison evidence from the so-called forensic lab and evidence from a paid informant whose recent released from a mental hospital was withheld from the jury;
  6. Det. Cook even groomed the probable killer into a star eyewitness before this witness died under mysterious circumstances;

Murphy, who had been in jail or prison for 20 years, had her sentence vacated by DNA evidence in 2014.

In the 1995 trial, prosecutors argued that certain samples of blood at the crime scene did not belong to the baby. Subsequent DNA testing showed that was incorrect, documents say.

Murphy's attorney's claimed the baby was killed by 14-year-old neighborhood kid William Lee, who committed suicide after Murphy's preliminary trial. According to court documents, Lee had a history as a juvenile delinquent. Lee is the one who called 911 from a pay phone in the neighborhood the night the baby died. He told dispatchers he was reporting a domestic situation, documents say. 

Lee later testified that he couldn't sleep and was walking around outside the apartment complex in the middle of the night when he heard Murphy and the baby's father arguing. He claimed that through the apartment windows, he saw Murphy carry the baby from one room to another, and the next time she appeared, she had blood on her arms and the baby was in the floor in blood. 

After his death, investigators took a sample of Lee's tissue in an autopsy to compare to the blood found at the murder scene. Lee had the same AB blood type as the baby. According to court documents, Murphy's genetic profile and Type A blood did not match the blood samples extracted from the crime scene, court documents say.

The case against Murphy was dismissed with prejudice, which prevents it from being refiled in the future.