A 19-year-old woman is last seen at a convenience store. More than a week later, her body is found in a yard outside a home in Springfield, Missouri. She has been stabbed multiple times.What happened to Mackenna Milhon?Joining Nancy Grace today:Rayne Mariee Davis- Dated suspect Lonnie Williams, has a 5-month-old son with Williams.Darryl Cohen- Former Assistant District Attorney, Fulton County, Georgia, defense attorney Cloyd Steiger - 36 years with Seattle Police Department, 22 years homicide detective & author of "Seattle's Forgotten Serial Killer: Gary Gene Grant" Dr. Bethany Marshall - Psychoanalyst, Beverly Hills Dr. Michelle Dupre - South Carolina Medical Examiner & author of “Homicide Investigation Field Guide”Jason Wert - Journalist, owner of Ozarks Independent.com