Born November 9, 1953, in Fort Pierce, Florida, Demps attended public schools in St. Lucie County, graduating from Fort Pierce Central High School in 1971. He began painting in the fifth grade and met A. E. Backus while on a school field trip to Backusâ€™s studio.
At age thirteen, he began painting the skies in the background of Alfred Hairâ€™s paintings and after he graduated from high school, he painted for a time with Sam Newton at Newtonâ€™s studio on Avenue D.
A graduate of Florida A & M University, Demps served in the U. S. Marine Corps before becoming a physical education teacher and high school football coach in Fort Pierce. Demps has since retired and now paints several hours a day. He is known as the Surrealist Highwayman. He married Shearon Hill and has three children.