In addition to his legislative duties, Waller works as an insurance agent. Prior to his election to the legislature, Waller served as the Jefferson County Clerk for four years, as well as the Jefferson County Executive and Treasurer before that.

A 1980 graduate of Festus High School, Waller received his associate's degree in Business Administration from Jefferson Junior College - Hillsboro in 1982, and his bachelor's degree in Public Administration from the University of Missouri - St. Louis in 1985.

Waller has served as a member of several boards and organizations, including the Missouri Association of Counties, the Missouri Clerks Association, the Missouri Treasurers Association, the Jefferson-Franklin Community Action Corp, the East-West Gateway Council of Governments, the COMTREA Mental Health Fund Board, the EDC of Jefferson County, and the YMCA of Jefferson County. He has been awarded the 110 Percent Award by KTJJ and was nominated as the Boy Scouts of America's Man of the Year.

Born in Festus, Waller currently resides in Herculaneum with his wife, Trina. They have three children and one grandchild. Waller is a member of Grace Life Chapel in Pevely.