The Missouri Supreme Court on Tuesday overturned the murder conviction of Mark Woodworth, 38, who has spent most of the last 20 years behind bars for the 1990 shooting death of his neighbor, Catherine Robertson, and for the armed criminal assault on her husband, Lyndel.

Woodworth, who was 16 at the time of the shootings, has maintained his innocence since he was indicted by a Livingston County grand jury in 1993. He was convicted in 1995 on the charges and sentenced to 31 years in prison. After briefly being released on appeal, he was convicted by a second jury in 1999, and was ordered to serve four life sentences.

In the opinion issued Tuesday, the Supreme Court stated that prosecutors withheld evidence that could have benefitted Woodworth's defense against the charges. Their 6-0 decision stated that convictions against Woodworth should be vacated, and that he be discharged from custody within 60 days, unless the state elects to retry him. Nanci Gonder, press secretary for Missouri Attorney General Chris Koster, told the Constitution-Tribune today (Wednesday) that it is the state's intent to pursue a third trial.

"This will require cooperation with the Livingston County prosecutor and the Livingston County sheriff in order to achieve this end," Gonder stated. "We will be reaching out to them this week, and asking them to transfer all evidence in this case back to Jefferson City immediately."

Woodworth's attorney Bob Ramsey said he was not surprised by the state's response, but plans to file paperwork with the court asking that the state Supreme Court remove the attorney general's office from the case and, instead, appoint an independent prosecutor who would decide whether a third trial should be pursued.

The Supreme Court's decision is considered a win for Woodworth.

"I feel like a ton of bricks has been lifted off my shoulders," said his mother, Jackie, shortly after the decision was rendered. "I'm not sure it's all sunk in just yet."

Ramsey has already filed a motion for bail so that Woodworth can be released. The state has until Jan. 16 to file a response.

Ramsey was on the phone with Mark Woodworth when they learned together of the Supreme Court's decision around 1 p.m. Tuesday.

"He was very, very happy," Ramsey said. "I know what I have gone through in the last 11 years. I cannot imagine what it has been like for him."

The Robertson family, although not surprised, expressed disappointment with the Supreme Court's opinion and supports another trial against Woodworth.

"We will fight to keep our mother's murderer behind bars all the way through the third trial," said Rhonda Oesch, a Robertson daughter. "I would also like to emphasize that the Supreme Court had the option to exonerate Woodworth and they didn't. He in no way was named innocent."

Tuesday's Supreme Court decision follows the recommendation by Boone County Circuit Judge Gary M. Oxenhandler, who was appointed as special master on the case, and who said that Woodworth's conviction should be set aside. The recommendation was based, in part, upon what became known as the "Lewis letters." The Lewis letters were correspondence between Livingston County Circuit Judge Kenneth Lewis (who called the grand jury), Lyndell Robertson, and County Prosecutor Doug Roberts. The letters had not been shared with the defense, and were not publicly disclosed until 2009.

Among the letters was one in which Lyndel Robertson wrote Lewis, expressing frustration with the county prosecutor's handling of the case against Woodworth. The master believed the letters to be favorable to Woodworth because they diminished Lyndel Robertson's credibility. In one letter, the county prosecutor indicated that Robertson at one point had been adamant that an ex-boyfriend of one of the Robertson daughters, Brandon Thomure, be charged for the shooting crimes. Yet, in a following letter to Lewis, Robertson declared that injustice would not be served until the judge brought the evidence against Woodworth before a grand jury.

Oxenhandler found that both the Lewis letters and the police reports of the violations by Thomure of one of the Robertson daughters' ex parte order of protection constituted evidence favorable to Mark, which should have been, but was not, produced by the state, and that suppression of it by the state, even if inadvertent, was prejudicial to the defense. The master also found substantial evidence to support Woodworth's allegation that the state suppressed testimony of two other people who said they provided material and exculpatory evidence concerning Thomure to sheriff's deputies shortly after the shootings that, if accepted, cast considerable doubt on Thomure's alibi at that time.

In issuing its 31-page decision, the Supreme Court stated support of the master's findings.

"The master found that the lack of this evidence impaired Mark's attempts to impeach key prosecution witnesses and that due to the weakness of the case against him, any additional advantage that could have been gleaned from this evidence might have resulted in a verdict of 'not guilty.'"

The Supreme Court also stated that, additionally, the master recognized numerous other pieces of evidence, which he believed supported Mark's argument that his second trial did not result in a verdict worthy of confidence.

The decision stated: "The master considered that this suppressed evidence along with the totality of the other evidence uncovered following Mark's last trial showed cause and prejudice and showed a violation of Brady that caused sufficient prejudice to undermine confidence in the outcome of the second trial and render the prior verdict no longer worthy of confidence."