FBI Persistency Paper – Episode 203

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Eric Ray and Glenn Langenburg review a new paper that’s been long in the making. The permanence of friction ridge skin and persistence of friction ridge skin and impressions: A comprehensive review and new results by Monson, et al. was recently published in Forensic Science International. The paper details the persistence and permanence of 1st, 2nd, and 3rd level detail over multiple years. There are important takeaways from the paper although it isn’t quite the level of the FBI/Noblis papers. So let’s see what the guys think.

Images from the Study

Figure 7: Permanence and persistence of level 1 detail of skin over a long term. Persistence, but lack of permanence, of level 2 and 3 detail: (a,b) mated skin photos at ages 30 and 40, with magnified areas above and below the central photographs. In (b), the core area is somewhat more elongated; there are more ridge breaks below and to the left of the core; a dividing ridge has become an ending ridge (lower arrow); and there are variations in pore size and shape (upper arrows and circled area).
Figure 8: Persistence, but lack of permanence, of level 2 detail of skin over a long term: (a, b) mated skin photos at ages 53and 61. The magnified areas are indicated by boxes. The arrow indicates where an ending ridge in (a) appears as a dot in (b). 
Figure 17: Lack of persistence of level 3 impressions over a short term: (a, b, c) mated ink rolled impressions collected in May, June, and August at age 26 show persistence of edge shape and ridge width (arrows); (d,e,f) mated ink rolled impressions collected in April, June, and August at age 31 exhibit variations in pore appearance (arrows); (g,h,i) mated impressions at age 27, where circled areas show variation in incipient ridges (April rolled ink, June inked flat, August inked flat, respectively).