since tracks made in soft earth, especially at high speed, are 
always shorter than the foot making them because of the 
push toward center at heel and toe. 
Getting check tracks for comparison is often ticklish 
business. An innocent man should not object to letting 
his track be measured, but he may take offense at the 
suspicion. Tact should be exercised not to antagonize 
innocent persons, although no one can be assumed to be 
innocent. If the evidence points to guilt, the tracks must 
be obtained. This is sometimes possible by indirection. 
In the case of human tracks, get the suspect to come out¬ 
side on some pretext and lead him across ground where he 
will leave a good track, which can be measured afterwards. 
Horses’ tracks may be measured in the same way. If the 
owner objects, use a search warrant. 
Auto tracks .—How to tell the travel direction of autos 
puzzles many investigators. On earth roads the follow¬ 
ing are indicators: Pattern imprint of nonskid tires, which 
is steeper and more distinct on the rear side of each in¬ 
dentation; stones which are shoved ahead by wheels, the 
track of the stone usually being intact close behind where 
it stops, and dust being piled by the shove on the forward 
side; imprint of partly imbedded stones slightly displaced 
by the wheels, the displacement being backward in very 
small stones and forward (or both forward and then back¬ 
ward) in those large enough to receive lateral as well as 
downward pressure; a sprinkling of sand or dust, which is 
found on the rear side of stones or other obstructions 
passed over by the wheel, while the forward side is usually 
swept clean; direction of skid on side slopes or against 
angling rocks or water breaks; the jump (when speed is 
sufficient) off the forward side of such obstructions, or in 
dropping into chuck holes; impact (wider tire imprint) 
on the forward side of chuck holes or against obstructions; 
action in ruts, where, in dropping in, a wheel will run 
off the high side to a featheredge, while in climbing out 
it will stay in the rut until side pressure forces it to climb 
out abruptly; the direction in which water drops, or mud, 
are carried out of a mudhole, or a stream ford; traction 
slips, which occur in going up steep grades; the turn on 
