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Lemuel Prion

Other Arizona Cases
On October 24, 1992, the severed arms of 19-year old Diana Vicari were found in a dumpster in downtown Tuscon, Arizona.  Vicari had disappeared several days earlier.  The rest of her body was never found. Soon afterwards, Tabitha Armentha, a 35-year-old prostitute, was kidnapped and sexually assaulted by a man at knifepoint.  Investigators believed that the two crimes were connected.
Police began to suspect Lemuel Prion, who had a criminal record and had often talked about sexually assaulting or hurting women.  In August 1993, investigators spoke to Troy Olson, a bartender who worked in the area where Vicari was last seen alive.  When they showed Olson pictures of Vicari and Prion, he recognized Vicari, saying she had been at the bar two days before her severed arms were found, but could not identify Prion.  Police also showed Armentha a mugshot of Prion, but she was unable to identify him.
In 1995, newspapers printed a photo of Prion, naming him as the prime suspect in the Vicari murder.  Olson then called the police and said that he now remembered Prion.  Prion, who was incarcerated in Utah at the time for an unrelated crime, was indicted for murder, kidnapping and aggravated assault on October 31, 1997. 
In 1999, Prion was tried for murdering Vicari and assaulting Armentha at the same trial.  Prion’s attorney wanted to introduce evidence indicating that another man – John Mazure -- had committed the murder.  Mazure saw Vicari the night of her disappearance, concealed information from the police when questioned, and “appeared at work the day after Vicari’s disappearance so disheveled and disoriented that he was fired.”  However, the judge would not allow this evidence at trial.  Olson testified for the prosecution, saying he had seen Vicari and Prion together on the last night that Vicari was seen alive.  The prosecution also called a Utah inmate who claimed that Prion had talked to him about committing violent acts against women.  On January 28, 1999, Prion was convicted of the first-degree murder of Vicari and the kidnapping and aggravated assault of Armentha, and sentenced to death.
In August 2002, the Arizona Supreme Court unanimously overturned the conviction, ruling that the trial court should not have heard Vicari’s and Armentha’s cases at the same time, and should have allowed the defense to present evidence indicating that another suspect had committed the murder.   On March 14, 2003, the Pima County Attorney’s Office dismissed all charges against Prion, and he was returned to Utah to serve out the remainder of his previous sentence.
- Alexandra Gross

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Posting Date:  Before June 2012
Last Updated: 5/2/2022
Most Serious Crime:Murder
Additional Convictions:Assault, Kidnapping
Reported Crime Date:1992
Age at the date of reported crime:30
Contributing Factors:
Did DNA evidence contribute to the exoneration?:No