Judge Ralph Erickson had no choice but to impose the death sentence, since that decision was made by a jury last fall.
"This is the most difficult day of my life," Erickson said, adding that he prayed for everyone involved in the case.
He then looked at Alfonso Rodriguez Jr., and said, "And I prayed for you, Mr. Rodriguez."
The judge told Rodriguez he had caused "pain that staggers the intellect." He called the kidnapping, rape and murder of Dru Sjodin "a crime that cries out to heaven for retribution."
Rodriguez stared straight ahead throughout the two-hour proceeding. He answered "no" when the judge asked if he wanted to say anything.
Rodriguez' sister and mother were in court to hear the sentencing.
"My heart has been torn into a million little pieces."
Before the sentence was imposed, 16 of Sjodin's family members and friends gave emotional victim impact statements.
Defense attorney Richard Ney also spoke, telling the court the death penalty will not make the community safer.
"This sentence does not reflect the heart of this community, it reflects the fear of the community," said Ney, who declined to comment further outside of court.
U.S. Attorney Drew Wrigley called the sentence fair and just. Wrigley said Alfonso Rodriguez caused a lifetime of pain for the family and friends of Dru Sjodin.
"We deeply regret the number of bad days there have been for Dru's family, initially and throughout. But I do think we have a sense of agreement -- there is a sense of peace in hard-won justice," Wrigley told reporters after the sentencing.
Peace will not come easily for Dru Sjodin's mother, Linda Walker. She says her daughter's violent death has torn her heart into a million pieces.
"There isn't a minute of the day that doesn't go by where I have the overwhelming void," said Walker. "Wanting to pick up the phone and talk to her, hear from her, hold her. I don't know that there'll ever be peace. I'm going to just have to somehow, once again, put one foot in front of the other and try to make sense out of the rest of my life."
Walker said she wants to escape the public spotlight she was thrust into three years ago. But she says her daughter's memory won't let her rest.
"As long as there are victims that are being taken by these sorts of people, then I do feel the need and compelled to keep it on the forefront of the national agenda of this country," said Walker.
Effecting some kind of change is also on the mind of Dru's father, Allan Sjodin. He says he's not sure what he will do, but he's certain he will continue to speak for his daughter.
"She's with me every second of every day. She's a constant thought. She's always there, patting me on the back and being part of my very being. That inspiration will never go and it's always a drive," said Allan Sjodin.
Defense attorneys filed notice they will appeal Rodriguez' conviction to the 8th Circuit Court of Appeals.
Rodriguez will soon be moved to death row at a federal prison in Terre Haute, Indiana, to await his execution by lethal injection. No date for that execution has been set, and it's likely that the appeals in the case will last for at least several years.