A recent story about an atrocity in the Middle East said officials had found many "bullet-ridden" bodies. However, I can't find any dictionary that accepts this usage. Shouldn't it be "bullet-riddled"?
The two words to riddle 'to fill with numerous holes; to put through a sieve' and riddle 'conundrum' are not related. The former is from the Middle English ridelen 'to sift' (< Old English hriddel 'sieve'), and the latter is from Old English rædels 'counsel; enigma, riddle; debate'. As for bullet-ridden: it's a common enough occurrence.
I've certainly heard it before, and there are more than 500,000 Google hits on it (though some are "riddled" and other things, as often happens when you search for a word in Google). Interesting that the dictionary doesn't cite it, but then we know about those dictionaries!
I have no idea if this is true, but my interpretation would be that "riddled" means the bullets are all over the man, but "bullet ridden" would mean he may have one, or more, bullets in him.