About Us The main focus of the Law Office of Mark A. Nelson is Family Law and related issues. Mark has over 17 years experience in dealing with, and successfully resolving, family law issues. Mark fights hard for the rights of his clients and works diligently to provide them with the highest level of legal representation. Mark A. Nelson started working for the San Diego District Attorney's Office in the Bureau of Child Support Enforcement in 1999 and established The Law Office of Mark A. Nelson in 2000. Since that time, Mr. Nelson has continued to provide his clients with superior legal services.