What is unusual about the man who tramples the child?

The man's face who tramples the child is unusual.

Explanation:

It is a normal enough face, but something in it strikes to the heart of Enfield, sending a shiver through his body, weakening his grip on the man's collar. It is a normal enough face - two eyes, not set too far apart or too close, two ears in proper alignment, a nose without a break, a mouth full of all its teeth even - but something in how it is all put together signals pure evil.