I agree. I also studied handwriting analysis a few years ago, just for fun. I found that most handwriting I analyzed (even writing of people I didn't know) were pretty accurate. But that was real handwriting, not printed block letters. I don't see how anyone could get a true analysis from block letters printed on an envelope. The writer obviously tried to disguise their handwriting. One thing I did notice though, is the downhill slant of the lines. If I remember right that indicates depression or discouragement. Also, the varying slant of the letters may indicate emotional confusion. Just the opinion of an amateur ;-)
I think that's one thing a reputable graphologist can zoom in on -- the "overstrokes" and indications of very slow, labored, heavy-pressured writing suggest deception. But even smart criminals don't know enough to disguise every aspect of their handwriting, so some clues may be gleaned.
The consensus among graphologists I've heard so far is that the writer may be of foreign extraction, but has lived in the U.S. for some time. That would seem to support suspicion of this suspect, Mohammed Pervez, a naturalized U.S. citizen who lived in Trenton: Suspects had bioterror articles [one named Pervez lived, worked in Trenton]
Also, where the writing is placed on the paper is also significant. All this is used routinely in clinical psych as a projective technique.