You can be sued for negligence. If you left the scene of the accident (you do not say whether you saw the sheriff there or later) you can be charged with that. Too many details are left out and there is too much missing information to fully make all the observations about your situation.
Check with a lawyer in your locale to discuss more of the details.
You might find my Legal Guide helpful "How to Choose A Lawyer For You"
NOTE: This answer is made available by the out-of-state lawyer for educational purposes only. By using or participating in this site you understand that there is no attorney client privilege between you and the attorney responding. This site should not be used as a substitute for competent legal advice from a licensed professional attorney that practices in the subject practice discipline and with whom you have an attorney client relationship along with all the privileges that relationship provides. The law changes frequently and varies from jurisdiction to jurisdiction. The information and materials provided are general in nature, and may not apply to a specific factual or legal circumstance described in the question.