Francis Wayne Alexander, a North Carolina man who moved to Chicago, would have been 21 or 22 when Gacy killed him some time between early 1976 and early 1977, the Cook county sheriff, Tom Dart, told reporters.

In a statement, Alexander’s sister, Carolyn Sanders, thanked the sheriff’s office for giving the family some level of “closure”.

Within weeks, the sheriff’s office announced it had identified one set of remains as those of William Bundy, a 19-year-old construction worker.

The details of Alexander’s life in Chicago are sketchy.

According to the sheriff’s office, the last known record of Alexander’s life was a traffic ticket received in Chicago in January 1976 – a year in which he earned little money.