The Supreme Court of Arizona

ADC#059399
Date of Birth: April 27, 1962
Defendant: Caucasian
Victim: Caucasian

On October 24, 1992, the arms of the 21-year-old female victim were discovered in a trash dumpster in downtown Tucson, severed below the shoulders and wrapped in plastic trash bags; she was identified through fingerprint comparison. The rest of the body has never been found.

Over the years Prion boasted and sang of taking a woman out into the desert, raping her, killing her, and cutting her up; this was ultimately discovered by Arizona authorities, who arrested him on October 31, 1997, while he was in prison in Utah.

During the investigation he was also connected to another incident in Tucson in late 1992 in which he kidnapped a woman and took her to a secluded area, threatening her with a knife; charges of kidnapping and aggravated assault from that incident were joined for trial with the murder of the first victim. 

PROCEEDINGS 

    Presiding Judge: Bernardo P. Velasco
    Prosecutor: David White
    Defense: Thomas Martin and John O'Brien
    Start of Trial: January 12, 1999
    Verdict: January 28, 1999
    Sentencing: August 20, 1999

Aggravating Circumstances: 

    Previously convicted of another felony involving use or threat of violence (the simultaneously-tried aggravated assault)    
      Especially heinous, cruel, and depraved 

Mitigating Circumstances: 

    Statutory-none proven 
    Non-statutory-family support

  

Lemuel Prion

On March 14, 2003, the Pima County (Arizona) Attorney's Office dismissed all charges against death row inmate Lemuel Prion, who had been convicted of murdering Diana Vicari in 1999.

In August 2002, the Arizona Supreme Court unanimously overturned his conviction, stating that the trial court committed reversible error by excluding evidence of another suspect.

According to the Supreme Court, "There was no physical evidence identifying Prion as her killer," and the trial court abused its discretion in not allowing the defense to submit evidence that a third party, John Mazure, was the actual killer.

Mazure, who was also a suspect in the murder, was known to have a violent temper, saw Vicari the night of her disappearance, concealed information from the police when they questioned him, and "appeared at work the next morning after Vicari's disappearance so disheveled and disoriented that he was fired."

The Arizona Supreme Court held that the third-party evidence "supports the notion that Mazure had the opportunity and motive to commit this crime. . . ."

Prion's conviction was based largely on the testimony of Troy Olson, who identified Prion as the man who was with Vicari on the night of her murder. However, when police first showed Olson photographs of Prion, Olson could not identify Prion. According to the Court, "[Olson] stated that the person in the photograph did not look familiar." Seventeen months later, after seeing a newspaper picture of Prion labeling him as the prime suspect in the Vicari murder, Olson believed he could identify Prion.

The Arizona Supreme Court also held that the trial court committed prejudicial error in failing to sever the Vicari murder trial from Prion's trial for another crime, stating "any connection between the two crimes is attenuated at best.” Prosecutors admitted that Prion would most likely have been acquitted if prosecuted under the standards set by the August 2002 ruling. Prion remained incarcerated in Utah for an unrelated crime.