FARGO, N.D. — A federal judge has thrown out the death sentence for a man convicted in the 2003 slaying of a North Dakota college student.

Judge Ralph Erickson ruled Friday that misleading testimony from a medical examiner and limitations on mental health evidence had violated Alfonso Rodriguez Jr.’s constitutional rights. He ordered a new sentencing phase be conducted.

Rodriguez has been on death row at a federal prison for nearly two decades in the death of Dru Sjodin, a Minnesota woman who was abducted from a Grand Forks mall parking lot in November 2003.

Rodriguez, a sex offender, was arrested the following month. Despite several massive searches, Sjodin’s body wasn’t found until the following April near Crookston, Minnesota.

In his ruling, Erickson wrote that Ramsey County Medical Examiner Michael McGee’s testimony had been “unreliable, misleading and inaccurate” about the cause of Sjodin’s death. He also wrote that Rodriguez’s attorneys did a disservice to Rodriguez by choosing to limit a mental health evaluation of their client that could have cost him a possible insanity defense.

“While it is beyond question that Rodriguez abducted and murdered Sjodin, the evidence now in the record has led the Court to conclude that errors were made that violate the United States Constitution such that due process demands a new penalty phase trial be held,” Erickson wrote.