Joshua Greaves

Prosecutors told a Butler County judge Friday they worry that a key witness in the Bosko murder case is at risk of dying from a heroin overdose, and that the testimony would be critical for an eventual trial.

“There were only three witnesses to this murder; one is dead,” Assistant District Attorney Ben Simon told Judge William Shaffer.

The three people prosecutors say witnessed the 2017 murder are: the victim, Gregory W. Bosko, 55, of Kittanning, whose throat was slashed; the alleged murderer, Joshua K. Greaves, 37, of Pittsburgh; and Tiffany Hilliard, 33, of Beaver Falls, Greaves' alleged co-conspirator who took a plea deal in exchange for her cooperation. Prosecutors allege that Greaves killed Bosko in March 2017 during a drug deal.

Hilliard, Simon said during a hearing before Shaffer, is a recovering addict, but is at risk of an overdose death. He asked Shaffer to allow them to record her deposition to obtain her eyewitness account of Bosko's death.

“Ms. Hilliard is doing very well, but it doesn't mean she doesn't struggle with her inner demons and a possible relapse. Preserving her testimony is of the utmost importance,” Simon said.

Hilliard pleaded guilty in August to felony robbery and abuse of a corpse. She was sentenced to 18 to 36 months in Butler County Prison. She was paroled in January and admitted to a drug rehabilitation facility.

Friday's hearing was held to address a number of issues between prosecutors and Greaves' lawyer, Christopher Capozzi, including recording Hilliard's testimony, the constitutionality of the death penalty being pursued by prosecutors, and the legitimacy of several warrants authorities executed to collect evidence against Greaves. Shaffer will make a decision later.

Capozzi also criticized prosecutors for cutting a deal with Hilliard.

“She admitted to planning the homicide, as testimony shows, and the (District Attorney's office) decided to not charge her with conspiracy to commit homicide,” Capozzi said. “Hilliard was a co-conspirator even though she wasn't charged as one.”

Capozzi previously argued against the prosecution's pursuit of executing Greaves if he is found guilty, and during a hearing in August, Capozzi said he would withhold his arguments pending an expected Sept. 11 decision from the state's Supreme Court regarding use of the death penalty. But in late September, the judicial body declined to hear the case, leaving the matter once again unresolved. Gov. Tom Wolf issued a moratorium on all Pennsylvania executions in 2015, calling the death penalty system “flawed.”

Capozzi's colleague, Michael Waltman, took up the argument Friday, arguing that the pursuit of the death penalty varies between counties, with some counties pursuing the measure more often than others. “That can't be constitutionally sound,” Waltman said.

“As we sit here today, it is still constitutional in the state and the United States,” Assistant District Attorney Robert Zanella said. He also addressed his office's deal with Hilliard.

“She was cut a deal by our office and that was done to seek justice,” Zanella said.

Waltman also invoked the Equal Protection Clause, a post-Civil War clause added to the Constitution's Fourteenth Amendment that inspired the phrase “equal justice under law.” He argued the disparity in charges between Greaves and Hilliard could be explained by gender. Because Hilliard is a woman, Waltman said, she was treated gently, while Greaves, being a man, was treated harshly.

Capozzi and Waltman also argued against prosecutors' use and collection of evidence against Greaves. On Friday, they asked Shaffer to remove evidence authorities collected from Greaves' Facebook account and data collected from his phone.

Friday's hearing addressed the remaining issues that stand in the way of Greaves' trial commencing. Once the issues are resolved, prosecutors and authorities will begin picking a jury, and a trial date is expected for next year.