A man accused of killing his 19-year-old girlfriend is pleading not guilty. Jon Clark is reportedly the last person to see Kiera Bergman alive before she vanished in early August. Her body was found about a month later west of Phoenix.
Law enforcement officials say Clark and Bergman may have gotten into some sort of argument before her disappearance. Clark was arrested on unrelated charges. He's charged with second degree murder and tampering with physical evidence.