What did Enfield say he saw in The Strange Case of Dr. Jekyll and Mr. Hyde?

Enfield said he saw a man (Mr.
Hyde) run into a little girl and trample her body, then run away.

In the beginning of the story, Enfield and Mr. Utterson are taking a walk when Enfield
points out a door and remarks on a strange sight he saw there.

Well, sir, the two ran into one another naturally enough at the corner; and then came
the horrible part of the thing; for the man trampled calmly over the childs body and left her
screaming on the ground. (ch 1)

Enfield describes this as
hellish to see.  He saw Mr. Hyde, grabbed him, and brought him back to the screaming child. 
Enfield comments that everybody loathed to see the sight of the man, except for the doctor, who
did not seem to care.

They arranged for him to pay 100 pounds to the family,
and he went  into the door that Enfield pointed too and came back with a check.  He was curious
about the strange house and the terrible man, and inquired as to his name.  He found out then
that his name was Mr. Hyde.

When Mr. Utterson asks Enfield to describe this
horrible looking man, he cant be precise.

He is not easy
to describe. There is something wrong with his appearance; something displeasing, something
downright detestable. I never saw a man I so disliked, and yet I scarcely know why. (ch
1)

This first exposure to Mr. Hyde is mysterious, and
foreshadows his later actions.  The incident with the check, so carefully described, hints at
Mr. Hyde having a keeperof course we do not find out until later that he is actually Dr.
Jekyll.  Mr. Hyde does not care about the girl because he cares about no one and
nothing.