For some reason I'm stuck on the idea that the recorder appears to have been a lefty...

Actually I have the card itself (and 5 others like it) and there aren't any fingerprints on the back on any of them, so I am guessing they were kept separate, as you suggested. The Henry system sounds very interesting-I had never heard of it until now. I'll have to do some research!

This wasn't the time before fingerprints - the New York Police began taking fingerprints in 1906 and Scotland Yard had been taking them since 1901. By 1912 one would suspect it was a fairly common process. I suppose it's possible that this guy's prints were on the other side of the card, although it may be more likely that they were kept separate and sorted using one of the various classification systems, like the Henry system. Once you found the correct prints you could then pull the identification card with the full details.

Yes, and, at the time, the minutiae were considered important in determining characteristics of criminals, so the then-popular eugenics movement could improve on the species (when Nazi Germans did this, it quickly extinguished any popularity of eugenics in the US).

For further info, see Biological Theories of Crime: A Historical Overview by Nicole Hahn Rafter, from the 2000 exhibit Searching the Criminal Body: Art/Science/Prejudice at the University at Albany University Art Museum.

You may also find the Eugenics Archive fairly fascinating.

Imagine the filing system...

A is A.

It's odd to see the metric system listed as the primary unit set. In the days before fingerprints, you'd need all these varied measurements to make sure you had your suspect. I wonder if he got to keep his hat.

Note the highly detailed and precise notation of seemingly secondary bodily specs. My presumption is that these would of great importance when a suspect's description needed to be transmitted to distant points, this being the days before wirephotos... I mean before faxes... I mean before the Internet.