The case of the missing Lyon sisters, Sheila and Katherine is Montgomery County's longest open cases. It received so much media attention back in 1975 because their father, John Lyon was a radio announcer and personality with WMAL AM radio. The station owner also owned Channel 7 TV and the Washington Post Newspaper. So this case received a lot of coverage.
Unfortunately, there just was not much evidence. The strongest lead to a suspect were several corroborated reports about the middle aged man in the brown suit with the tape recorder in a brown briefcase. Sheila and Kate were seen talking to that man, as were several other children. Police sketch artists drew a composite sketch of the suspect, and when this was published, about 15 new leads came in from other persons who had seen a man who resembled the sketch and fitting the description a few days earlier at two shopping centers in neighboring Prince Georges County. The man was never identified and no one ever came forward claiming to be him.
The extensive media coverage generated many tips and leads over the weeks, months, and even years following the girls disappearance.
I wrote the story that is repeated on most of the linked websites. It is long, but as concise and factual as I could be. There was much, much more information available in news paper stories, and certainly in Montgomery County Police files. At one time, those police files filled twenty three large boxes. There are probably more now. The case is still considered open and active.
Mr. Lyon is now a counselor who works with families who have lost a child. He was mentioned in the news a few years ago, when he provided support to the father of little Michele Dorr. Michele, also of Montgomery County, Maryland had been murdered by Hadan Clarke, in 1986 and buried near White Oak Naval Weapons Center. She was missing for 13 years before prosecutors got a conviction (without a body) on Clarke. After his conviction, Clarke led investigators to her grave.