Heflin was last seen in Oktibbeha County, Mississippi on January 1, 1969. He has never been heard from again. He and his wife of six years were separated at the time of his disappearance; she had taken their two sons and moved to Chicago. She learned about his disappearance from a relative.

Heflin may have been involved in some kind of illegal action with a man in Longview, Mississippi. One of his friends gave him a ride to the man's house and heard Heflin arguing with the man, and when Heflin came outside he was crying and said he couldn't say what had happened because it would put his friend's life in danger. His friend urged him to go the police, but Heflin refused, saying the man had threatened to kill his family.

Heflin's wife stated he would occasionally drop out of sight for months at a time, but she didn't believe he would have permanently abandoned his children. Although there's no hard evidence of foul play in his disappearance, it hasn't been ruled out. His case remains unsolved.