A naked woman robbed a bank. Nobody could remember her face.

Reminds me of another old joke:

 

Three professors from Oxford University were sunbathing on a nudist beach.  One of them spots the university Vice Chancellor approaching in the distance.  The professor of Greek grabs his towel and wraps in around his waist.  The professor of Latin does the same.  However, the third professor wraps the towel around his head.

 

After the Vice Chancellor has passed, the professor of Greek asks the third professor why he didn't wrap the towel around his waist.  The professor of Logic replied that normally he was recognised by his face, not his external genitalia.