Practical Instruction for Detectives

Having been connected for many years with two of the largest and most successful private detective agencies in this country, both as an operator and as an official, and having been requested to outline briefly and concisely the most modern and up-to-date methods employed by leading detectives and private detective agencies of today, I shall confine myself in these pages to facts and a few personal experiences. I will endeavor to show that any person possessed of average intelligence, and wh...