Martha Moxley. Courtesy photo

Connecticut prosecutors are gearing to challenge the state Supreme Court’s decision to vacate Kennedy nephew Michael Skakel’s murder conviction, with an appeal to the highest court in the nation.

In a motion filed Tuesday, 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 State Supreme Court should have the opportunity to address this case and the issues it raises,” Killen wrote.

Skakel is the nephew of former Sen. Robert F. Kennedy’s widow, Ethel Kennedy. He was convicted in 2002 of the beating death of his 15-year-old Greenwich neighbor Martha Moxley. He spent 11 years in prison for the murder. But on May 4, the Connecticut Supreme Court vacated his murder conviction, finding Skakel’s first attorney, Mickey Sherman, failed to present evidence of an alibi.

By a 4-3 ruling, the divided court ordered a new trial in the case that had garnered national and international attention. It granted Skakel’s motion for reconsideration, reversed the earlier decision and issued a new judgment.

“The circumstances here warrant a stay of this court’s judgment and any consequent proceedings to enforce that judgment pending certiorari review by the United States Supreme Court,” Killen argued.

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

“Both of these issues were extensively debated by the majority and dissenting justices of the court, and are not frivolous,” according to the motion.

Skakel’s lawyer, Bridgeport-based Michael Fitzpatrick, referred all comment to co-counsel Hubert Santos, who did not respond to a request for comment by press time.

Meanwhile, some legal experts say getting the U.S. Supreme Court to accept the case would be a tall order.

The U.S. Supreme Court hears about 80 cases a year, or about 1 percent of petitions, according to long-time Connecticut lawyer Wesley Horton, a partner with Horton, Dowd, Bartschi & Levesque in Hartford.

Horton said the odds are small that the high court will hear the Skakel matter. To get the high court’s attention, prosecutors would need to show the case involves a major federal question of great public importance, or demonstrate a conflict with a ruling from another state supreme court.

Also important to note: prosecutors missed the 20-day window to file the motion for stay in the state court, following the Connecticut Supreme Court ruling on May 4. Their motion seems to rely on an exception that extends the deadline under ”the most extraordinary circumstances.”

“The undersigned takes responsibility for missing the 20-day deadline. Nevertheless, not counting the three-day holiday weekend, only two days have passed since the deadline for timely filing,” according to the motion. “No further proceedings have, as yet, commenced in the trial court. The petitioner is not incarcerated. There would appear to be no prejudice to the petitioner, nor any significant interference with the expectations of the trial court, should this motion for stay be entertained by this court at this juncture.”