Standard Practice for Latent Print Evidence Imaging Resolution

Importancia y uso:

5.1 The procedure described in this document is in accordance with current SWGFAST guidelines (6), as well as National Institute of Standards and Technology (NIST) standard (7), which specify 1000 pixels per inch (ppi) at 1:1 as the minimum scanning resolution for latent print evidence. This standard appears primarily to be historical and directed towards scanners, rather than cameras, though recent studies suggest that it is suitable for capturing Level 3 detail (8).

5.2 While the 1000 ppi resolution standard permits the capture of level three detail in latent prints, it does not mean that any image recorded at a lower resolution would necessarily be of no value for comparison purposes. Such an image could have captured level two details sufficiently for comparison. However, there are some latent print impressions that are so degraded or contain such limited quantity of information that at least 1000 ppi resolution is required to conduct an accurate examination. Some automated fingerprint identification systems require 1000 ppi for submission purposes. The relationship between machine (optical) resolution and achievable resolution (sometimes called resolving power) can vary greatly by manufacturer (8).

Subcomité:

E30.12

Referida por:

E1732-24E01

Volúmen:

14.02

Número ICS:

35.240.15 (Identification cards. Chip cards. Biometrics), 37.040.99 (Other standards related to photography)

Palabras clave:

forensic science; digital camera; digital flatbed scanner; imaging resolution; latent print; resolving power;