Michele Mallin said she was "100 percent sure" when she identified Timothy Brian Cole as the man who raped her.

Her resolve never wavered, Ms. Mallin said, until she learned last May that DNA testing had invalidated her 1985 identification. The revelation came nearly nine years after Mr. Cole died at 39 in a Texas prison from an asthma attack.

"I was more shocked than I think I had ever been in my entire life," Ms. Mallin said during a recent lawyers workshop in Fort Worth.

(ht: How Appealing) And all too common; Brandon Garrett of the University of Virginia identified faulty eyewitness testimony as the leading cause of convictions later overturned via exculpating DNA evidence:

The 200 exonerees were convicted based on eyewitness identifications (79 percent), forensic evidence (55 percent), informant testimony (18 percent), and false confessions (16 percent).

I can’t tell you the number of times a witness has told me one thing in trial preparation and another on the stand. Are they lying? No. Mistaken? They don’t think so.

Memory is fallible. People are fallible. Stick it on your door, your computer, your trial bag, and your notepad. Always question eyewitness testimony, no matter how sure or how sincere. And if your theory of the case isn’t robust enough to survive some changes in testimony, you need to rethink it.