The mug shots from some of these collections are pretty intriguing and, at least on the surface, they appear to reflect the personalities of their subjects. There are also records of prison inmates, descriptions of criminals in custody and at large, and criminal culture, such as the "Alphabet of Thief Slang" index below.
Above is a page from Prison Record Book for San Quentin and Folsom prisons, 1904-1911 (BANC MSS 89/44). One volume of this collection contains prisoners' pictures, while the other has their records and descriptions of their crimes. More from this collection below:
(Can you profile a criminal based on the shape and style of his- or her- hat?! Hmm, let's see, we've got bowlers, pork pies, and even a floral ladies hat. With all these fashion choices it's impossible to tell the bank robbers from the cold-blooded assassins!)
A particularly interesting piece of prison history also exists in the Bancroft's manuscript collections in the form of a scrapbook of various criminals, composed by the Sheriff's Office of Woodland, in Yolo County, California. Titled the Edward F. Boyle Mug Book, 1875-1899 [BANC MSS 91/26], it contains some very rich descriptions. I particularly like the "Bad Egg" page. Transcriptions are included:
at Alcatraz Island
American 20 years of age- 5 feet 9 1/4 inches in stockings-
dark complexion- [blear?] skin- no whiskers- small black eyes- black hair- small mouth. [R.S.M.] and the American Flag in Indian Ink on left arm.
Old Man Winnie
American 44 years of age- 5 feet 2 1/2 inches high- light complexion- blue eyes- hair turning gray bald head- Rum Nose- face covered with Rum Blotches. Served 1 term of 4 years in San Quentin.
Index of Thief Slang: [note that the columns switch]
Burn a House = Glim a Crib
Pistol = Pop
Tumbled or Dropped = Got Suspicious
Jimmy = a Chisel for Prying
Hand Cuffs = [Darbies]
Pete = Lock
Breaking a Lock = Make Pete Laugh
Crabs = Shoes or Mockisins (sic)
--- D. Miller