For more than forty years, Kim Parmer has been haunted by the prospect that someone murdered her cousin, Sandy Beal, in 1977. Award-winning reporter Melissa Jeltsen investigates the mysterious death of a teenage girl in Prince George's County, Maryland. 

If you or someone you know is considering self-harm, please contact the National Suicide Prevention Lifeline at 1-800-273-8255, or text "STRENGTH" to Crisis Text Line at 741-741.

• The story that brought Kim to Melissa