There are other explanations for why an "innocent" TRM would not come forward. It is possible (although remote) that he never heard about it. Perhaps he was a recluse who did not follow the news or watch TV. The possibility gets less remote if, say, he died or left the area right afterward. While the Lyon sisters' disappearance was big news in Maryland, I wonder if someone in Mississippi would have heard much about it. Most people I encounter and discuss the case with have never even heard of the Lyon sisters. I've found that generally only people who lived in the DC area in 1975 know about it.
Emery,
Thanks for your very insightful comments. The Tape Recorder Man or "TRM" as many refer to him remains to this day a mystery man. Certainly, it is possible that this guy was simply a weird guy with a newly acquired tape recorder, or an innocent hobbiest. But the circumstances all tend to argue against that. The fact is that the girls did, in fact, disappear on that day in March 1975 shortly after being seen talking to TRM. And TRM seemingly disappeared about the same time.
I agree with you in that he probably was only at Wheaton Plaza for a brief time on 25 March 1975. He may have polished his approach or techniques at other malls first, then decided to make his move on the day in question. Had he been an innocent old guy with a hobby of talking to kids on his lunch hour, he would likely have spent more time at it, and probably would have been seen and remembered by more people that day.
With regard to my earlier remarks about possible "tainting" of evidence by posting a suspect's photo alongside artist's composite drawings - or older photos - I agree that it would have to be a decision made by a judge, but any knowledge of such an on-line comparison would certainly call the question, and it would almost certainly be used by the Defense Attorney to help his client to introduce doubt to the jury. I have seen cases in which eye witness testimony was not allowed because of faulty line-ups, showing of photos, or questioning by police.
You are also very correct about the unreliablity of eye witness descriptions and testimony. Sometimes composite drawings are way off, while at other times they look like they were drawn from life. In the case of "Jimmy" and his un-named buddy, they remembered TRM for a number of reasons. First and foremost, "Jimmy" knew both Lyon sisters quite well because he lived close to them and because he rode the same school bus as Sheila. He recognized them and wondered about the guy they were talking with, even hearing a portion of the conversation. He pointed the guy out to his buddy and they commented about his tape recorder and wondered if they, too, might get to be interviewed. They saw him walk away.
Immediately after the sketch was published, a number of other people came forward and claimed to have seen the same man. They could not add much to "Jimmy's" description or to the drawing, although the same artist did make a slight alteration to the sketch in the mouth area based on their comments.
My biggest concern would be the estimated age (50), which I think Jimmy based on TRM's gray or "salt and pepper" hair. Height might have been off as well, since the man was probably sitting most of the time (as was Jimmy and his friend). Also, recall that in 1975, it was a very popular style to wear boots or high heeled shoes which were covered by flare or bell bottom style trousers. Such a shoe might add a couple of inches to a person's height.
In regard to news coverage of this story - even though the war in VietNam was the main story because of the fall of Saigon, the Lyon Sisters were THE STORY in the Washington DC Metropolitan area, and they stayed front page news for weeks, in the papers, on radio, and on TV. It was, however, picked up by other papers throughout the country because there were Associated Press (AP) feeds the went out. I recently posted one such story printed in Marin County, California.