The Missouri Supreme Court has overturned the murder conviction of man who had been sentenced to life in prison for the 1990 slaying of a woman on a neighboring farm.Mark Woodworth was convicted twice in the shooting death of his neighbor, Catherine Robertson. He is serving a life sentence. The state’s high court ruled Tuesday that prosecutors “withheld material, favorable evidence from the defense” that could have helped Mark Woodworth defend himself against accusations that he killed Robertson in her home in Chillicothe and assaulted her husband. Woodworth’s father farmed with Robertson’s husband.In a sweeping 6-0 decision, the court ordered Woodworth’s convictions be vacated and that he be discharged from the state’s custody within 60 days, unless prosecutors decide to retry him.Woodworth’s attorneys say his conviction was tainted by prosecutors’ failure to turn over copies of letters that cast doubt on his guilt, as well as other evidence that would have benefited the defense.ABC 17 News reported in May, Circuit Judge Gary Oxenhandler ruled that Woodworth was the victim of “a manifest injustice” and should have his conviction set aside.Attorney General Chris Koster had asked Oxenhandler to revise his ruling. Oxenhandler’s unchanged decision was then transferred to the Missouri Supreme Court.The high court appointed Oxenhandler in November 2010 as a special master in the case to review new evidence submitted as part of Woodworth’s latest appeal. The prosecutor in the original case was former Columbia congressman Kenny Hulshof. He was also the prosecutor in the cases of Dale Helmig in 1996 and Josh Kezer in 1992. Both of those men were convicted of murder and later had their convictions overturned.ABC 17 News tried to reach Hulshof for comment back in May, but did not hear back.