How did a wealthy widow wind up dead below a staircase in her mansion?

Beverly Hills detectives responding to the death of 67-year-old Violet Yacobi — who was found on the marble floor below a staircase in her mansion — suspected foul play and her dentist son, and wondered if the family fortune was a motive for murder.

source https://www.cbsnews.com/news/violet-daniel-yacobi-beverly-hills-staircase-mansion-murder-48-hours/