How can you have "tissue" that has an incomplete DNA sequence?
That doesn't make any sense at all.
B-sharp, aren't you a biologist? Please, I need your expertise here. Is it possible for a fresh biological sample large enough to be considered "tissue" not to have the complete DNA within?
I certainly appreciate the confidence in my knowledge but I'm not a biologist, just someone who spends time researching as fully as possible most responses.
Much of my knowledge is from the years I spent on TalkOrigins.
As far as your post is concerned, without doing any additional research I would agree with you, each skin/fat/muscle cell contains a full set of DNA. If the sample contained only partial cells, which is possible, some DNA may be missing from each cell but a full set should be reconstructible. If however they found only erythrocytes (red blood cells) no DNA would be found. This isn't likely though.
I think the point that was made is that tissue under the fingernail goes to the interaction of the two and their personal intent, therefore in this instance, the 'who' may not be as important as the 'why'. (I know little about this particular case so I'm just throwing out ideas).