A federal appeals court has affirmed the death sentence for a convicted sex offender who kidnapped and killed a college student just six months after being released from prison.

In an opinion released Tuesday, the 8th U.S. Circuit Court of Appeals denied Alfonso Rodriguez Jr.'s attempt to overturn his death sentence.

The Crookston, Minn., man was convicted in 2006 of kidnapping resulting in the death of student Dru Sjodin three years earlier.

Sjodin, a University of North Dakota student from Pequot Lakes, Minn., disappeared from the parking lot of a Grand Forks, N.D., shopping mall where she worked.

Her body was found near Crookston five months later. Authorities say she had been raped, beaten and stabbed.

Rodriguez previously served more than 20 years for offenses that included rape and attempted kidnapping.

Rodriguez has remained in federal prison in Indiana awaiting execution while his lawyers argued the appeal.

The prosecutor who sent Rodriguez to death row, U.S. Attorney Drew Wrigley, said the case captured national attention because Sjodin was abducted while walking to her car after shopping. It could have happened to anybody, Wrigley said.

"There was this raw feeling that there was no way to protect against this," Wrigley said.

State and federal lawmakers have since tried to bolster that protection. A dozen new laws against sex offenders have been enacted in North Dakota since Sjodin was killed. Minnesota has taken similar steps. The names of victims have been attached to federal legislation, including the Adam Walsh Child Protection and Safety Act, Katie's Law, and Dru's Law.

North Dakota Attorney General Wayne Stenehjem said the case created an intolerance toward sex offenses that was long overdue.

Click here to view the memorial Web site maintained by Sjodin's family.