Don was born July 5, 1942, in Sinton, Texas. He attended Baylor University in Waco, Texas, receiving a BBA degree in Management and Economics and after graduating joined the US Navy and went to Officer Candidate School in Rhode Island. After his Honorable Discharge from the Navy, Don worked for Central Power and Light Company in Corpus Christi, Texas until he entered Baylor Law School. He graduated from law school in August 1970 and passed the bar in the fall of that year. Don practiced law in South Texas for several years and was a Partner in Nicolas and Morris in Corpus Christi before moving to Weatherford, Texas in 1976. Don has now been a practicing attorney for 52 years. The first 30 years of his professional career included 7 years of primarily corporate practice in the field of Oil and Gas and Administrative Law. The next 23 years Don had a general trial practice with 16 of those years as a partner in Vick, Chrestman and Carney in Weatherford, Texas. 

In March 2000 Don won the Republican Primary in Parker County, Texas, as a candidate for District Judge of the 43rd District Court of Texas. After winning the general election, Don took office early when he was appointed by then Texas Governor George W. Bush, and he served until his retirement of 31 December, 2010. Since his retirement, Judge Chrestman has taken Senior Status, and serves as a visiting Judge for the 8th Administrative Region of Texas. He also began his Mediation practice and has mediated hundreds of cases in the DFW area. Judge Chrestman brings 57 years of legal and business experience to the table for judicial and mediation practice in the State of Texas and the United States.