The U.S. Supreme Court has denied certiorari in Connecticut v. Skakel, leaving in place a state Supreme Court decision that vacated Kennedy cousin Michael Skakel's conviction in the 1975 murder of Martha Moxley.

Represented by Bridgeport attorney Michael Fitzpatrick, Michael Skakel successfully argued in May that he was denied a fair trial, after being charged in 2000 and convicted in 2002 for beating 15-year-old Moxley to death with a golf club. Skakel, who was also 15 at the time of the murder, was Moxley's neighbor in the Belle Haven section of Greenwich.

Skakel spent 11 years in prison for the murder but was freed in October 2013. The state Supreme Court reinstated his conviction in 2016, but last May the court ruled 4-3 that Skakel's first attorney, Mickey Sherman, had failed to present evidence that would have exonerated Skakel, including testimony from witness Dennis Ossorio.

The state has not announced its intentions regarding a possible retrial of Skakel, who is a nephew of Robert F. Kennedy's widow, Ethel Kennedy. Monday's decision allows to stand a May 4 Connecticut high court decision to throw out Skakel's conviction based on inadequate representation.

Connecticut prosecutors announced shortly after the state Supreme Court's decision to vacate in May that they would appeal to the highest court in the nation. In a May 29  motion, Senior Assistant State Attorney James Killen asked the Connecticut high court to delay executing its judgment while prosecutors petition the U.S. Supreme Court to hear the case.

“Because this court's decision is grounded exclusively on federal constitutional law, the United States Supreme Court should have the opportunity to address this case and the issues it raises,” Killen wrote.

The motion asked the court to determine whether Connecticut's Supreme Count was wrong in finding Skakel's legal representation “to be constitutionally inadequate,” and made a mistake in not weighing the evidence “in a manner consistent with the jury's guilty verdict.”

Prosecutors missed a 20-day window to file the motion following the Connecticut Supreme Court ruling May 4, relying on an exception that extends the deadline under ”the most extraordinary circumstances.”