Haven’t been on in a long time so forgive me if this has been brought up, but listening to the true crime garage podcast yesterday they brought up a valid point that has never made sense. Why just a letter to Rachel’s Tommy? Why not letters to all the girls families? This completely voids any kidnapping to me...Changes my entire thought process.
Well, there are different thought processes on the letter. As you know, many people on this forum (and the FB page) suspect TT as being accountable for the disappearance. Some of them believe the letter wasn't mailed and he married it to an extra envelope later. I've never believed that (nor do I think it was TT). I think there are too many circumstances that would have had to have been present for that to be the case. I wrote a post on it a while back if you search for it.
Another thought process is that if the girls were abducted by a stranger, he sent it to Rachel's house because she was the only one with a driver's license, which would have had her address. In that scenario, I guess she could have had provided her husband's name as well. Or it could have been looked up in the phonebook.
I've repeatedly said I think there's a good chance the letter isn't actually related to the case, but rather was sent by someone who merely wanted to inject themselves into the story. People do things like that all the time (calling in false reports, harassing families with fake phone calls, etc.) and the location of the car was discovered by 6pm. The letter was postmarked the following morning, plenty of time for the letter to have been sent by anyone. (btw, LE said the postmark is valid years ago, I don't know why people including True Crime Garage continue to go down the postmark rabbit hole. Its a waste of time). I'm not saying this was the case, just saying I think its a real possibility.
At any rate, if the girls were kidnapped and the letter was sent by the abductor/s it makes complete sense to me that they would have sent only one letter and not 3. Not only would writing 3 letters be time consuming but since the letter and the envelope don't appear to be written on a matched set of stationary it would leave you to believe that they wrote it on whatever they happened to have on hand in their vehicle, etc.