I've said it before, I'll say it again, just because you're smart at one thing does not mean you're smart at everything:

Jurors found Linux programmer Hans Reiser guilty of first degree murder on Monday, concluding he killed his estranged wife in 2006. The verdict followed a nearly six-month trial and nearly three days of deliberation.
...
When police eventually located Hans Reiser's Honda CRX a few miles from his home, they found the interior waterlogged, the passenger seat missing, and two books on police murder investigations inside. They also found a sleeping-bag cover stained with a 6-inch wide blotch of Nina's dried blood...

Fans (such as myself) of CourtTV and/or various court TV dramas will rightly surmise that even though the evidence was almost comically incriminating, it was also completely circumstantial. It's the kind of stuff good defense attorneys love to sink their teeth into, because cops can and do fake stuff like this all the time. So why did he get convicted? Because of a counter-example to Scott's Plaintiff Principle: never ever ever take the stand in your own defense:

In a characteristic exchange under cross-examination, Reiser tried to explain why he'd removed and discarded the passenger seat from his two-seater Honda CRX after Nina vanished. His explanation: He'd been sleeping in the vehicle, and wanted the extra room. Asked why he hosed down the inside of the car, leaving an inch of water on the floorboard, he explained that the interior was dirty, and he mistakenly believed the water would drain out.

The description in the article paints the man as a genuinely unpleasant person to be around, and in my opinion indicates he's suffering from a pretty severe mental illness. Which is sort of surprising to me, since I actually deployed ReiserFS on a few systems around here back in 2000, and the articles on his website seemed to me friendly and conversational.

Of course, it's not known as a "descent into madness" because people start off nuts, eh?