Re: How are fingerprints read?

The most common type of  fingerprints are loops (no designation to left or 
right slant), then whorls, then arches.  The proper way to describe loops 
would be to call them either ulnar or radial.  Ulnar loops are those in 
which the slant points towards the ulnar bone of the arm (the little 
finger side of the hand).  Radial loops are those in which the slant 
points towards the radial bone of the arm (the thumb side of the hand).  
As an examiner, we look at the impressions a finger leaves when 
classifying it, never the finger itself. 

So, in this example, if this woman inked her thumb and placed an 
impression on the paper, it sounds like her loop was going in this 
direction \. Since this is her right hand, this is a ulnar loop with a 
right slant.  If she actually looks at her hand, it appears to be a left 
slant, however it is not. Ulnar loops are the most common loop, on the 
right hand they will have a right slant and on left hand a left slant.  If 
you have a loop on the right hand that has a left slant, that  would be a 
radial loop.  Conversely, a left hand with a right slant loop would also 
have a radial loop.  It all comes down to which bone the loop is opening 
to and what hand it is on. 

Hope this helps.  If you have any more questions, just ask!