His father, Wexford Karr, married Patricia Elaine Adcock on Aug. 21, 1958. He was 37 and she was 18, according to court documents.
Their union produced two sons, Michael and John, who was born Dec. 12, 1964.
The couple separated 11 years after they married, and Wexford Karr filed for divorce in 1973 in Clayton County, saying the marriage was "irretrievably broken" and that the boys were in his custody. His wife received a $5,000 mobile home and $125 a month in alimony, according to court papers.
Soon after, Wexford Karr, then 52, married a woman 23 years his junior, Susan Simpson. But his union with the 29-year-old burned out in divorce six months later.
John Mark Karr moved to Alabama to live with grandparents when he was about 12. He grew up in Hamilton, a town of 7,000, graduating from the local high school.