44 
Witnesses can be grouped broadly into two classes, those 
who will tell the truth, and those who probably, or cer¬ 
tainly, will not. This resolves itself chiefly into a question 
of motive. Persons having no interest in the offense or 
the offender will generally tell the truth; the testimony 
of those who have such an interest is apt to be prejudiced. 
However, it should not be overlooked that persons of the 
latter class may be upright enough to tell the truth if 
questioned, while fear of unknown consequences may 
swerve a disinterested witness from the path of truth. 
Truthful witnesses may again be divided into those who 
are willing to tell what they know and those who are 
reluctant to do so. Most people are of the latter kind. 
The average American not only has an exaggerated unwil¬ 
lingness to testify against a wrongdoer, but is himself so 
busy that he does not want to get mixed up in other peo¬ 
ples’ troubles if he can avoid it. The person who is 
anxious to tell on another has usually some grudge, and the 
influence of this on his testimony must be carefully 
weighed. 
You can help your own judgment of men by systematic 
study, in your everyday business, of truthfulness, the 
motives of untruthfulness, etc. A careful study of cases 
where you believed and were mistaken will reduce your 
own credulity. Lack of truthfulness is very common, 
and a man who fails to state the exact truth is not always 
in league with crime. 
Study of previous testimony of a lying witness helps. 
A man nearly always sticks to the same lines of mental 
side stepping in such things as justification of his own 
conduct, and throwing suspicion on others. 
Attitude of officer .—Much of the success to be gained 
depends upon the investigator’s attitude. Judge your 
man. Be short, snappy, commanding with the bold; 
patient and considerate with the timid. Unnecessary 
officiousness, or insolence, or contempt, however, will shut 
up most men like a clam. Courteous and considerate 
treatment will open a man’s heart—and probably his 
mouth—especially if others have just treated him harshly. 
