I was reading about the Leopold and Loeb case and it seem to indicate they could tell who wrote a letter as each typewriter is unique. Is this the case? How were they able to see that it was an underwood typewrite that typed the note?
Yes it is. The typeface of each brand and model differs in subltle ways.
First there are two different sizes: pica and elite.
Then things like the shape of curly-cues on the letters varies. Some typewriters have numeral 1s, others use a lower case “L.”
Individuals machines can also be IDed if there are irregularities, like broken misalligned letterforms, raised/lowered/slanted keys and faulty carraige shifters.
There is an old guy in NYC who is a professional typewritter expert. He gets hired by police to narrow down the make and model of a typewriters using samples of the typed text.
Prior to inkjets and lasers, in order to transfer text to paper, you had to physically press ink against the paper. In typewriters, this took the form of metal hammers with the characters embossed on them. Each manufacturer had their own version of any given font–in the olden days, it was nearly always something resembling Times Courier New–but they were sufficiently distinct that a person who worked with them constantly could recognize the font from any given manufacturer (and sometimes by model).
In addition, since the hammers were not perfectly aligned, (and people typed with different strengths in different fingers), each individual machine developed characteristic patterns for each character. (This is very analogous to the threads on a gun barrel that will leave a distinctive mark on a bullet.) It is not at all hard for an experienced person to recognize generally the manufacturer (and, in special cases, the model) of typewriter that created a document. Once the typewriter is identified, the actual idiosyncratic characteristics of the keys can be used to confirm that a given machine created a particular document. (This was harder once IBM Selectrics made changing the type and font a matter of changing a steel ball covered in characters, but it could still be done.)
Before the anti-Communist Revolution, all typewriters in Romania had to be registered with the government and identified by a page of typing.
That’s nothing!!
I watched a Discovery Channel documentary about the CIA. They have this laser they shoot at an officer window. The laser picks up the vibrations from the person in the office typing. It then interprets the vibrations as characters and the CIA can tell what is being typed!! Now that is nuts!!
To counteract this, the CIA headquarters is a building inside a building. Between the inner and outer walls and ceiling runs a current of air. This muffles out both sound and vibratons.
wait, wait!
what the hell? Bear_Nenno, did they really say that? that you could tell which letters were being typed by the sound of the typewriter? i’ve heard of ultra-sensitive laser microphones which can pick up conversations indoors while the mike is hundreds of feet away. but what you said implies that you can tell letters from differences in the “clack”, and i can’t swallow that.
We’ve been through this before:
http://boards.straightdope.com/sdmb/showthread.php?threadid=27338
I was just as shocked when I heard it too, JB.
The identification of typewriters by the font and peculiarities of type also shows up in a Sherlock Holmes short story, although I forget which one. Any Doyle fans out there know?
And the thing with the lasers and typewriters is total bull. If you’ve got a view of the window, why not just look in with a powerful telescope and see what’s being typed?
Someone on this board (No, I don’t remember who) said that he works in a building within sight of the CIA headquarters. He said that it struck him as very strange that he never saw anyone inside the CIA HQ, and speculated that all the exterior offices were just facades. This building-inside-a-shell thing seems to fit into this observation.