She landed two master's degrees in public health, then worked for nonprofits, including Flying Doctors of Africa, descending on hot spots in Rwanda and elsewhere.

FORBES: Charity--For a Profit

But like a moto magician, Sopheng turned the handlebars this way and that, minutely steering a course between puddles, somehow avoiding the slickest spots that would have sent us flying, gunning the engine moments before we got stuck, fording fathomless puddles when that was the only way, and all with a serene smile.

BBC: Piecing together puzzles in Cambodia

Keyes also was meticulous and methodical, flying to airports in the Lower 48, renting cars, driving hundreds of miles searching for victims, prowling remote spots such as parks, campgrounds and cemeteries.

WSJ: Trying to unlock secrets of dead serial killer