OKLAHOMA CITY (KFOR) – Oklahoma Attorney General Gentner Drummond and attorneys for death row inmate Richard Glossip will appear before the U.S. Supreme Court on Wednesday to ask the court to grant Glossip a new trial. Glossip has always said he is innocent in the case that dates back nearly 30 years. The Supreme Court will consider overturning Richard Glossip’s murder conviction in Oklahoma In 1997, Oklahoma City motel worker Justin Sneed admitted to killing the motel’s owner, Barry Van Treese. At trial, Sneed testified that Glossip, who was the manager of the motel, paid him $10,000 to kill Van Treese.   In exchange for his testimony against Glossip, prosecutors did not ask for Sneed to be put to death. In 1998, a jury found Glossip guilty for Van Treese’s murder and sentenced him to death. Glossip was retried in 2004, and again found guilty and sentenced to death. Glossip’s execution has been scheduled nine different times since 2015. His attorneys say he has been served a last meal three different times. Glossip’s executions have been delayed due to concerns over Oklahoma’s lethal injection drug, and legal challenges from Glossip and his attorneys, who claim Glossip did not have a fair trial. Glossip’s attorney, Don Knight, told News 4 prosecutors knew Sneed—their key witness—lied on the stand when he testified against Glossip, but they never told anyone.   OK Attorney General files brief with Supreme Court asking to halt Glossip execution “Two independent investigations well discovered information that shows that Justin Sneed was lying about his use of whether he was prescribed lithium, whether he was under the care of a psychiatrist at the county jail,” Knight said. “The prosecutor at the time knew these things to be true. And she didn't correct Snead at all.” Oklahoma Attorney General Gentner Drummond stepped in after his office discovered a box with key evidence inside had been destroyed and never shared with Glossip’s defense team before trial. “The prosecutor has an extra burden to make sure their witnesses are telling the truth and to make sure they've given all the evidence, including evidence that might benefit the defendant to the defense before the trial onset,” Tulsa-based attorney Tim Gilpin told News 4. In a statement to News 4, Drummond said he believes prosecutors violated Glossip’s rights by withholding evidence from his defense team, writing: “After a comprehensive independent investigation, I believe it is clear that prosecutors committed a Brady violation by not sharing potentially exculpatory evidence with the defendant and violated Napue by knowingly allowing false testimony that prevented the defendant from receiving due process. Oklahomans deserve to have absolute faith that the death penalty is administered fairly and with certainty. I don’t believe that justice is served by executing a man based on the testimony of a compromised witness.” Oklahoma Attorney General Gentner Drummond After numerous appeals at the state level, the case’s fate now lies in the hands of the U.S. Supreme Court. Oklahoma death row inmate had three ‘last meals.’ He’s back at Supreme Court in new bid for freedom On Wednesday, Drummond and Glossip’s lawyers will appear in Washington D.C. to argue for the U.S. Supreme Court to grant Glossip a new trial. Glossip’s defense team says the fact that Drummond is willing to get involved, should speak volumes. “An attorney general of a deeply-conservative state can see that a person did not get a fair trial and has the courage to stand up and say this person did not get a fair trial and we are not going to execute someone who didn't receive a fair trial,” Knight said. “It is imperative in our system for all of us that we have the opportunity to have a fair trial. In a brief filed with the U.S. Supreme Court, attorneys for Barry Van Treese’s family asked for Glossip’s conviction to be upheld, writing: “The Van Treese family has waited patiently for justice for 10,047 days, and yet, they are now witnessing the spectacle of their case being stalled by the attorney general for their home state confessing an error where none exists.”