43 
Sometimes, however, he can not do it because the whole 
community knows him, and the guilty ones and all their 
sympathizers would soon know what he was after. In 
such cases a special man, whom nobody knows, will prob¬ 
ably have better luck, and the assignment of such a man 
may be requested. 
GETTING A LEAD. 
In deciding to whom to go for possible evidence the 
best guide is again a carefully built-up mental picture of 
the case—a working theory. 
If possibilities permit, eliminate at once the busy- 
bodies who always claim to know all about every happen¬ 
ing, and go after those who really know most or were first 
on the ground. If nothing better develops, figure out a 
tentative suspect on some ground, such as most probable 
motive, and start on that basis. If your tentative sus¬ 
pect should not be the right one, questions implicating 
him are likely to draw from an honest witness indications 
as to the true suspect when he would not have given them 
in reply to general questions. 
Before doing this, however, it will be desirable to get 
preliminary information as a protection against witnesses 
lying or otherwise trying to mislead. It is indispensable, 
as soon as any real line-up begins to appear, to consider 
every scrap of information which is at hand or can be 
gleaned with respect to family, business, or friendship 
relations of possible suspects, so as to safeguard giving 
away anything unwittingly. Use every opportunity to 
get from fair-minded witnesses information on the trust¬ 
worthiness and connections of others who must be dealt 
with. 
HELPS TO INTERROGATION. 
Knowledge of men .—In this work, nothing else can make 
up for a knowledge of men. A witness will tell nothing 
or make but inaccurate and unimportant statements to an 
investigating officer who lacks shrewdness and tact, while 
the very same witness will make precise, true, and im¬ 
portant statements to an officer who can read and knows 
how to handle him. 
