Martin was last seen at her home in Lincoln, Illinois on June 2, 1976. Her husband was the last person to see her, before he left for work at 6:00 a.m. Martin was supposed to go to work at 9:00, but she never arrived and has never been heard from again. After her disappearance, her vehicle was found abandoned in the parking lot of the Holiday Inn in Bloomington, Illinois. Martin did not check into the inn, however. Her car had a flat tire and bloodstains in the trunk when it was found.

Martin was scheduled to testify against Russell Smrekar, who was accused of shoplifting two steaks (worth $4) from a Kroger grocery store. He was subsequently convicted of murdering Robin and Jay Fry and was sentenced to 200 to 600 years in prison. He is eligible for parole every three years, but has been denied every time. Jay was the store clerk who saw Smrekar try to steal the steaks and was going to testify against him at the trial. Robin was Jay's wife, and was pregnant at the time of her death. Smrekar was also believed to be responsible for Martin's disappearance and for the disappearance of Michael Mansfield, a witness against him in an unrelated burglary case, but he was never charged in connection with their cases.

A photograph of Smrekar is posted below this case summary. In October 2011, shortly before he died in prison, he confessed to Mansfield and Martin's murders. He said he buried Martin's body under Interstate 55, which was under construction at the time, late at night on the same day of her disappearance. He was unable to give a precise location, however. Investigators announced that, in light of Smrekar's confession, they were closing Martin and Mansfield's cases.

Martin was employed as a real estate agent at the time of her disappearance, and she has two children. Her husband died two years after her disappearance. Her body has never been found.

Above: Smrekar, circa 2006