When reading Ron Hendry and his 'professional' opinion, one must remember that he believes in the innocence of Amanda Knox.
http://www.injusticeinperugia.org/RonHendryclasp.html
The December 18 photo above shows a close-up of the same side of the clasp shown under the pillow. Note dirt debris around clasp. Note the damaged and nearly torn off hook. Note the blood soaked thread strands