i just finished a book by jack olsen, "misbegotten son" (the "misbegotten" refers to the genetic abnormalities discovered in shawcross during pre-trial workups which likely contributed significantly to his crimes.) last chapters deal with pyroluria. fascinating and tragic. many lives might have been saved if this knowlege had been available. the book is about serial killer arthur shawcross. his kryptoluric ? levels were found to vary up to 10 times normal levels along with other genetic abnormalities. if you are sensitive/ dislike grisly or explicit material then just skip to the end where the psydoc (krauss?) is working up a report for the courts.