It's been nearly five years since 22-year-old Dru Sjodin's half-naked body was found in northwestern Minnesota.
Alfonso Rodriguez Jr. was convicted for her death in 2006.
This morning, her father, Allan, sat through the first in what may be a series of appeal hearings on behalf of Rodriguez.
Sjodin and his former wife, Linda Walker, said they have an obligation to keep their daughter's memory alive.
"That is that somewhere along the line, that Dru's death won't be in vain, nor will everyone else that's suffering these terrible crimes," Sjodin said.
Rodriguez's defense attorney Robert Hoy didn't dispute that the convicted sex offender kidnapped Dru Sjodin from the parking lot of a Grand Forks shopping mall, or that he raped and killed the young woman and dumped her body in a ravine.
But Hoy said the crime shouldn't cost Rodriguez his life, and he offered a series of technical arguments to three judges from the 8th Circuit Court of Appeals.
Hoy told the judges that testimony about two previous sexual assault cases should not have been allowed. Jurors were given details about the crimes, for which Rodriguez served decades in prison.
The defense attorney said the cases weren't legally serious enough to have been considered as the aggravating factors that a death penalty requires.
But the U.S. Attorney for North Dakota, Drew Wrigley, told the judges it was appropriate for the jury to consider previous sexual assaults Rodriguez had committed.
Rodriguez served 23 years in prison, and was considered at heightened risk to attack more women when he was released. That was just six months before Sjodin disappeared from the parking lot of a Grand Forks shopping mall.
The prosecutor in the case also argued that the depravity of the slaying and the interstate kidnapping also qualified Rodriguez for the federal death penalty.
Wrigley talked about the future of the case outside the courthouse in St. Paul this morning. He is likely to be replaced by a new federal prosecutor to be named by the administration of President Barack Obama.
"The case is going to go into a different phase now, get into more what I'll call a hyper-technical sort of litigation about appellate issues," Wrigley said. "But it's always going to be capably handled in that office."
"I know the depth of commitment to the case in the U.S. Attorney's office of North Dakota, and in the Department of Justice," Wrigley continued. "We're going to litigate this case, we're going to fight to convict that verdict to the very end. It was justly won, and correctly decided by that jury."
Neither Minnesota nor North Dakota have a death penalty.
The case was charged by federal authorities because Sjodin was kidnapped in North Dakota and found dead in Minnesota.
A decision on the appeal is likely this summer, and both sides expect an appeal to the U.S. Supreme Court.
Alfonso Rodriguez Jr. is now being held on federal death row in Indiana.