Lambda the Ultimate

Okay, it's not quite the right place for this, but I'm stumped and many of you keep tabs on this kind of stuff.

A long time ago I ran into a paper on something I remember being called "statistical defect detection", wherein some clever people wrote software to record which branches were taken leading up to a crash and used those to determine, statistically, which lines of code were most likely to be responsible.

I can't find it any more. Can anyone else remember it? Maybe you can help me find it?