The ransom note printed S. B. T. C. at the end of the note.
The question is, what does this stand for?
Our profile predict that the killer left clues to who he is. It's like a game he was playing.
Profile:
The killer travels on foot, bike and bus. The travel with a back pack. He enjoys rock climbing and walking the trails.
He sleeps in a tent and know how to stay warm by tucking his two white blankets tight to his body at night to stay warm. It just like the Indians did with their child out on the trails, like a papoose. He knows how to tie knots when he is climbing high off a cliff. This rock climbing makes him fearless just like committing a crime in a house with the family asleep.
He has learn to carry small bills like $20.00 because he does not want to bring back coin change, this is added weight and will cause noise out on the trails.
He know that he may need help out on the trails and some times to place a call to check in with family. A cell phone was not a option back in 1996 and also the distance location of cell towers. So he know how to connect to phone line wires out on the trails. He uses the Red and the Green wires. In the crime scene he painted a GREEN strip on JonBenet chin with paint from the paint tote and with ink, a RED smiley face on her hand. He uses his own phone hand set to connect to phone lines when he can to place a call FREE on his travels.
Boulder CO and other areas in the parks have phone boxes that he can easily tap into using his phone hand set to make a call. He only connect to the Red and Green wires.
He also knows that the basement of houses is wear the phone line connection are made to a house, this is called the phone line block. The basement is a place that is very well known to him and he fill at home in the basement.
Most houses do not have the alarm wired to the basement windows and some time the doors. Easy in and a easy out and it will be warm and dry. He knows all about wires and wear they are.
Phone box:

S.B.T.C. may be stamp on his phone hand set that he keep with him in his back pack.
Southern Bell Telephone Company.
This was one of two items very importance to the killer to complete this crime. He added this information to the end of the ransom note as a clue.
The other was used to monitor the house and the family for days or weeks before the crime, The spotting scope Victory brain.
S.B.T.C.
Victory
Note, he may have also left this clue in the form of some items place on the kitchen table that the Ransom family did not know how it got there.
A Silver spoon wall place in a bowl of fresh cut pineapple, next to this was a used tea bag place inside a glass drinking cup.
S = Silver spoon
B = Bowl
T = Tea bag
C = Cup
A small black child metal ball bat is kept in his backpack for protection out on the trails. No gun permit is required.
A black child metal ball bat was found at the crime scene and was not source to the Ramsey's family.
The ransom note call was to be place between 8 and 10 AM. One of the yellow emergency phone boxes located up in the hills could have been used for this call, just tap the phone box using the Red and Green wires and this line if trace by police would ID the location to a call box up in the mountain. No person's name connected to this phone line if the police was to check it out.
Team JBI