Sarah Stultz, AlbertLeaTribune.com

Oral arguments in the appeals case of convicted murderer Robert Michael Hughes began Tuesday in the Minnesota Supreme Court of Appeals.

In October of 2006, an Olmsted County jury found Robert guilty of the first- and second-degree murder of his estranged wife, Tammy Hughes, after police found her shot to death in the Hugheses&8217; Albert Lea home on May 25, 2005.

After the conviction, Hughes was sentenced to life in prison without parole at a Minnesota correctional facility in Stillwater.

In January of 2007, Hughes and his attorney filed an appeal with the Clerk of the Appellate Courts within the Minnesota Supreme Court.

The appeal alleges that the prosecution failed to prove beyond a reasonable doubt that Robert premeditated the death of his wife and that his conviction for first-degree premeditated murder must be reversed.

It also argues that the trial court in the initial trial failed to give a complete instruction on first-degree premeditated murder and to clearly instruct the jury on the lesser offense of second-degree intentional murder.