So far, it appears that LE has conducted something of a witch hunt against Richard Welch. They have no evidence whatsoever linking him to the Lyons sisters' disappearance, and, in fact, they claimed last month (Jan. 2015) that physical evidence would be found at Taylor's Mountain (where Richard Welch owns some property). Guess what? Nothing was found.
So where does that leave us? An embarrassed LE releasing press conference statements impugning RW via laughable extrapolations: Richard and his wife were "very interested" in what relatives might have told police (who wouldn't be?); Thomas, the (then 10-year-old) nephew named in Lloyd's fantasy alibi as being in the car at the time of Richard's alleged involvement (Thomas said this never happened), "very unusually" called his uncle after the press conference. Apparently, Thomas doesn't normally call his uncle to wish his uncle "Happy Birthday", so obviously, something must very definitely be up if he called his uncle following a televised LE press conference which merely named his uncle as someone who may have kidnapped, raped, and murdered two young girls and which named himself as a material witness, right?
I believe Thomas called his uncle way before either he (Thomas) or the uncle (Richard) were named publicly.
The top of page two of the search warrant attachment:
http://ftpcontent.worldnow.com/wset/SKMBT_60115022314160.pdf
"on the day of the press conference naming Lloyd as a person of interest" the phone calls between Thomas and Richard were made and they met for several hours at Richard's house.
The press conference naming Richard as a second person of interest was months later, and I believe Thomas was not named publicly until last Friday.
It is unknown to us, but there is a good chance that neither Richard or Thomas was known to the police at the time of the first press conference.
That being said, that a close relative was named as a person of interest is an innocent reason for telephoning and meeting in person for several hours.
There are also less innocent reasons, such as getting the stories straight.
My own individual guess is that at most Richard, after the fact (murder), helped dispose of the bodies, but at this time, you are correct that there is little public information that is convincing against anyone. Even Lloyd's criminal record is unlikely to be usable as evidence against him.
Richard, Thomas, and Richard's wife did initially cooperate with the police and gave, according to the police "conflicting" reports of what they talked about that day. But almost any two or three reports are slightly conflicting. In fact if the reports were word, for word, we talked about A, B, and C, I would venture the police would the reports not as conflicting, but as "unusually identical."
My own guess is that Thomas came to the attention of the police from calling his uncle, but this is a guess.
It is unknown how or when (before or after Lloyd was named) Richard came to the attention of the police.
My speculation is that if Richard really was a serious person of interest at the time of the announcement, the police would have had better surveillance on him, any person of interest, to see if any attempt was made to cover up evidence. If, and it's a big if, the police knew about Richard and Richard has some guilt, they could have caught him by taping the phone calls (warrant required) or catching Thomas off guard the same day.