Dean is a lifetime resident of Sioux Falls, South Dakota, a 1966 graduate of Washington High School, and a 1970 graduate of the University of South Dakota (Majors: Government and History; Minor: Spanish). Dean also attended USD Law School, where he graduated in 1973. He has continuously maintained both a general law practice and a trial law practice in downtown Sioux Falls since April 1, 1974. For the last 25 years Dean has worked side-by-side with his wife of more than 40 years, Carole. Carole is a registered pharmacist who serves as Nasser Law's office manager and Dean's legal assistant. They were joined in the practice of law by their son, Jimmy Nasser, in 2009 and by their daughter-in-law, Jolene Nasser, in 2013.

Dean is one of the most experienced lawyers in the state of South Dakota. He is an AV rated lawyer, which is the highest rating a lawyer can receive from his peers. Dean has argued in front of the South Dakota Supreme Court nearly 50 times and was named the 2010 - 11 South Dakota Trial Lawyer of the Year. Dean has attended dozens of advanced trial seminars and is a graduate of the elite Gerry Spence Trial Lawyers College.

Dean also spends a significant amount of time helping the South Dakota Legislature and Governmental Agencies draft laws that promote and preserve the interests and rights of everyday South Dakotans. Odds are, if you live in South Dakota, Dean's efforts have likely had an effect on the insurance policies you buy and/or the laws your employer must follow to regulate a worker's compensation claim.