Key points are not available for this paper at this time.
Paul L. Kirk, Professor of Criminalistics, University of California, Berkeley, California, is well known to the readers of this journal and to all active in the field of criminalistics. Professor Kirk has published a number of articles in this and other technical journals, and is the author of Crime Investigation (Interscience Publishers, 1953). His present paper has been prepared from material presented before the California Association of Criminalists of which he is an active member.-EDITOR.
Paul L. Kirk (Sat,) studied this question.