Handwriting examination by use of a powerful light and microscope enable law enforcement officers to find out if someone wrote something, which could be useful in the case of identity crimes as people often forge signatures.  
Type examination uses a similar technique as handwriting examination, but also involves checking inks and paper types for falsifications and potential leads to where the documents may have originated.
Photocopied documents, such as identification can be compared with the originals to determine if they are the originals, or examined on their own to find if they are photocopied.
Printed documents would be examined in the same manner as typed & photocopied documents, with more emphasis on the characteristics of what it was typed on and clues that could show where it came from.
Alterations and obliterations would be dealt with in a similar manner: both would be checked to reveal that they were in fact changed or removed, and then attempts would be made to discover what had been changed or obliterated.
In identity crimes, this is highly important, as identity thieves could use documents written by the actual person, edit them, and use them to their advantage if unchecked.
Most "questioned" documents can be checked for identity theft by comparing handwritings of the doubtful documents with a real handwriting.
Graphologists are usually psychology experts who assess personality traits from handwriting samples.
Forgery specialist's experts who analyze altered, obliterated, changed or doctored documents and photos using infrared lighting, spectrographic equipment, or digital enhancement techniques.
Forensic stylistics are like graphologists except they look at handwriting by looking at semantics, spelling, word choice, syntax and phraseology.
Handwriting analyst can tell whether a crime was committed through document examination.