In what scenarios would someone paranoid / secretive / foresighted enough to have a TL-15 safe in their home also be negligent enough to leave the $100k in cash behind when the sell they house? (And without any widow / family / "business associates" who would know enough to invest in the prompt services of a SAVTA tech?)
Of course it was empty! The money was under the third floorboard next to the room door. You've obviously not watched enough Columbo or "Murder She Wrote"