James Toliver Craig, a 45-year-old dentist from Aurora, Colorado, has been arrested on suspicion of murder in the death of his wife. She was taken to the hospital Wednesday evening after complaining of severe headaches and dizziness, but was declared brain-dead a short time later. Police believe she was poisoned and have obtained a warrant for first-degree murder. Craig is being held in the Arapahoe County Jail without bond and the investigation is ongoing.