The person who ran from the accident, if caught will typically have their license suspended if not cancelled or revoked for a lifetime.  Additionally criminal charges may be filed, with chances of jail time being quite high.  Many times insurance companies also revoke certain insurance policies due to the fact a "runner" from an accident is looked down upon in society.  Different states have different policies, however, it is not unusual to see fines or infractions if a pedestrian is hit.  In some states the fines raise if an animal was injured.