FARGO (AP) - A federal judge has denied a motion to throw out the death sentence for a convicted sex offender in the killing of University of North Dakota student Dru Sjodin.

Defense attorneys for Alfonso Rodriguez Jr., 53, of Crookston, Minn., claimed jurors failed to properly weigh evidence in the death penalty phase of his trial. A jury of seven women and five men unanimously voted Sept. 22 to sentence him to death.

Defense attorney Richard Ney asked that the sentence be changed to life in prison without parole.

U.S. District Judge Ralph Erickson, in a ruling filed late Monday, said the jury correctly decided the case on the value of each factor for and against the death penalty, rather than "sheer numbers."

"The evidence is sufficient to sustain a sentence of death," Erickson said.

A sentencing hearing has been set for Jan. 5. Ney said after the death penalty verdict that he would file a motion asking for a new trial.

Sjodin, 22, of Pequot Lakes, Minn., was abducted from the parking lot of a Grand Forks shopping mall in November 2003. Her body was found the following April in a ravine near Crookston.

Rodriguez was found guilty of kidnapping resulting in death. North Dakota does not have the death penalty, but it is allowed in federal cases.