Prince George's County Police Detective Bernie Nelson turns to genealogy after seeing another Maryland cold case solved after 28 years. Can the murder of Sherry Crandell be solved the same way?<p>See <a href="https://omnystudio.com/listener">omnystudio.com/listener</a> for privacy information.</p>

It was a case nightmares are made of. A D.C. power couple, their 10-year-old son and housekeeper held hostage for nearly 24 hours and murdered inside a burning D.C. mansion. WTOP examines the complicated trail of evidence that police say led to finding their killer and why they say he committed such a brutal crime.