OKLAHOMA CITY (KFOR) — The case of a high-profile Oklahoma death row inmate went before U.S. Supreme Court Justices Wednesday morning. Richard Glossip was sentenced to death for arranging the 1997 murder of his former boss. Wednesday, the Attorneys for Glossip and Attorney General Gentner Drummond's office pitched their case and asked the court to grant Glossip a new trial. PREVIOUS COVERAGE: Drummond to argue before SCOTUS seeking new trial in Glossip case They argued there were recently uncovered missing pieces of evidence that would have changed the outcome of the trial. "Mr. Chief justice, and may it please the court, Richard Glossip was convicted on the word of one man, Justin Sneed, the undisputed murderer in this case," said Seth Waxman, an attorney for Richard Glossip. The case was later retried with the same outcome. "Oklahoma has now disclosed evidence revealing that Mr. Sneed lied to the jury about his history of psychiatric treatment, including the fact that a prison psychiatrist prescribed lithium to treat his previously undiagnosed bipolar disorder," said Waxman. "That was never disclosed in the original trial, which is a big difference," said Representative Kevin McDugle, R-Broken Arrow. However, an attorney arguing to uphold Glossip's conviction said the Oklahoma Court of Criminal Appeals has sided with the prosecution multiple times. PREVIOUS COVERAGE: Death row inmate Richard Glossip case to go before SCOTUS "The parties rely heavily on the attorney general's confession of error, but courts, not executives, determine whether to vacate final judgments of conviction," said Christopher Michel, an attorney arguing for Glossip's conviction to be upheld. Supreme Court Justices asked about Sneed's lithium use, which was disclosed in Glossip's second trial. It wasn't until recently that it was known who prescribed the drug and why. "The jury knew about the lithium, and what they didn't know is that it was prescribed by a psychiatrist. Do you? Do you really think it would make that much of a difference to the jury?," said John Roberts, U.S. Supreme Court Chief Justice. "As I understood it, no court has ever actually made findings on those things," said Supreme Court Justice, Ketanji Brown Jackson. Representative McDugle, who's been in support of a new trial, said taking the case to the U.S. Supreme Court is a step in the right direction. PREVIOUS COVERAGE: OK AG files brief in support of Glossip petition for U.S. Supreme Court case "I'm hopeful that the Supreme Court will agree that Richard Glossip can't be executed under these circumstances," said McDugal. Glossip has maintained his innocence over the years. The U.S. Supreme Court is expected to rule on the case by June of 2025. Representative McDugle said a ruling could come much sooner, but that's unknown. The Supreme Court has stayed Glossip's execution until after a decision is reached.