Lawyers for a man sentenced to death for killing a University of North Dakota student submitted a document Tuesday for what is considered the final step in the legal appeals process, claiming his trial team was ineffective and that the man is mentally disabled.

The 298-page document, a so-called habeas corpus motion, was filed in federal court for Alfonso Rodriguez Jr., who was convicted of kidnapping resulting in the death of Dru Sjodin of Pequot Lakes, Minn. Rodriguez, 58, of Crookston, Minn., is being held on death row at a federal prison in Terre Haute, Ind.

The appeal was filed by attorney Joseph Margulies, a Northwestern University law professor who has represented several death row inmates. U.S. attorneys in the case depicted Rodriguez "as little better than an animal, uncaring and unworthy," Margulies said.

"We now know this carefully scripted tale conceals much and reveals little. Little about the government's case, and even less about Alfonso Rodriguez, was true," the document says. "In the pages that follow, we describe in meticulous detail the difference between what was and what could have been."

Federal prosecutors were not immediately available for comment.

A Texas appeals court on Wednesday formally exonerated a former grocery store clerk who spent nearly 25 years in prison for his wife's 1986 beating death, reaffirming a judge's decision to set him free last week based on DNA testing that linked her killing to another man.

The Texas Court of Criminal Appeals declared Michael Morton innocent of killing his wife, Christine, and made him eligible to receive $80,000 from the state for each year of confinement, or about $2 million total.

Morton, 57, was convicted on the basis of circumstantial evidence and sentenced to life in prison. He maintained over the years that his wife and their 3-year-old son were fine when he left for work at an Austin Safeway the day she was killed, and that an intruder must have attacked her.

DNA found during tests this summer on a bloody bandana discovered near the crime scene matched that of a former convict, who remains at large. Prosecutors recommended that Morton be freed immediately after that man's DNA was also linked to a hair found 17 months later at the scene of another woman's beating death in north Austin, about 15 miles (24 kilometers) from the Mortons' home.