In non-fiction, the first document examiner to describe how a typewriter might be identified was William E. Hagan who wrote, in 1894, "All typewriter machines, even when using the same kind of type, become more or less peculiar by use as to the work done by them". Other early discussions of the topic were provided by A. S. Osborn in his 1908 treatise, Typewriting as Evidence, and again in his 1929 textbook, Questioned Documents.
In non-fiction, the first document examiner to describe how a typewriter might be identified was William E. Hagan who wrote, in 1894, "All typewriter machines, even when using the same kind of type, become more or less peculiar by use as to the work done by them". Other early discussions of the topic we,re provided by A. S. Osborn in his 1908 treatise, Typewriting as Evidence and again in his 1929 textbook, Questioned Documents.