You should contact a skilled criminal defense attorney as soon as you become aware that the police (or some other investigating agency) are looking for or investigating you, or if you believe that you may have committed a crime.
A lawyer can intervene with the police and either prevent an arrest or, if you are going to be arrested, arrange for your surrender at a time and in a manner that minimizes embarrassment to you or your family.
Hiring a competent lawyer in a timely fashion may also protect you from being questioned by the police. If questioned by the police, never answer any questions and always ask for an attorney to be present during any questioning, no matter where the attempted questioning takes place.