FARGO - Federal prosecutors say the appeal by a man convicted of killing a University of North Dakota student should be rejected and his death sentence should stand.

Alfonso Rodriguez Jr. of Crookston, Minn., is awaiting execution in a federal prison for the 2003 kidnapping and killing of Dru Sjodin, 22, of Pequot Lakes, Minn. His lawyers have appealed the verdict.

In the government's 216-page response filed with the 8th U.S. Circuit Court of Appeals on Wednesday, prosecutors said there were few mistakes made during the trial, and any possible errors were harmless.

"The judgment of conviction and sentence of death imposed in the district court should be affirmed," prosecutors wrote.

Defense attorney Richard Ney, a death penalty specialist from Wichita, Kan., said he didn't have a chance to review the document on Wednesday and had no comment. Later in the day, defense attorneys asked to extend the deadline for a response from two weeks to a month.

Defense attorneys have argued that the jury pool was biased and mistakes were made by U.S. District Judge Ralph Erickson and prosecutors. The Fargo trial was held in a community "contaminated by prejudice," the appeal said.

U.S. Attorney Drew Wrigley said in an interview that prosecutors tried in their response to add context to defense arguments.

"Context is our friend in this thing because it was a fair trial conducted by an experienced judge with excellent defense lawyers who were very thorough," Wrigley said. "That's a point we will defend all day long."

Sjodin disappeared from the parking lot of a Grand Forks mall in November 2003. Rodriguez, a convicted sex offender, was arrested soon after. Sjodin's body was found in a ravine near Crookston in April 2004.

The government said Rodriguez's trial was fair and impartial, noting that the jury pool was 12 times the normal size and defense attorneys were allowed to strike up to 30 potential jurors instead of the allotted 20. Lawyers also took 21 court days to interview jurors, the government wrote.

"The judge was being very thorough. Wherever there was a close call, it went in the direction of the defense," Wrigley said Wednesday. "I think that was very clear going through the transcript."

A defense complaint that Wrigley used improper language in closing arguments does not qualify as "misconduct such as would negate the jury's death verdict," prosecutors said.

The government is requesting that both sides have 60 minutes to argue in front of the circuit court, twice the time that normally is allowed. Wrigley said he expects the case to be heard by early 2009.

"I always caution people that this is an important part - not a begrudging part - of our work to defend this verdict until the very end," Wrigley said. "What's really on trial at this point is the trial itself."