Jennifer Yoak - Technical Leader
2023 Update -
The Latent Print Section is implementing a policy allowing for limited or deferred comparisons in certain situations. The intention behind this change is to provide the most conclusive and potentially probative results more quickly. Comparing latent prints from the tips or joints of the fingers, or unknown areas of the palms, to list a few examples, is very time-consuming and often leads to inconclusive results unless we receive carefully recorded known prints concentrating on a specific anatomical region.
Once we have searched and/or compared all AFIS quality prints in a case, we may choose to defer comparison of the remaining latent prints – those that are NOT suitable for database searches – if they are present on the same or similar surface/item as any latent prints that have been identified (e.g., exterior surfaces of a vehicle). The report will clearly state if comparisons have been deferred, and the remaining latent prints will be fully compared when a request is received.
Our expectation is that this will be reserved for cases with large numbers of latent prints, or cases with identifications to multiple individuals, when limiting the comparisons will save a significant amount of time in reporting the initial results. Any latent prints with the potential to identify an additional individual, or present on a different item or surface, will be fully compared before reporting. We also remind agencies to list the name and demographic information of any individual you would like compared in a case, as AFIS searches can occasionally miss the source of a latent print even if that person has known prints in one of the databases searched.
The Latent Print Section processes and analyzes various items of evidence in an attempt to identify or exclude who may have touched an item or surface. Several different chemical processing methods are used at MVRCL to recover latent (invisible to the naked eye) finger, palm, and – on occasion – bare footprints from items of evidence. Examiners also examine lifts that have been taken at the scene and submitted by investigating agencies. When latent prints of value are recovered, they can be compared with the known prints of the person or persons associated with the crime. The Latent Print Section maintains an Automated Fingerprint Identification System (AFIS), which includes a digitized database of known fingerprints and palmprints. These known prints can be used for direct comparisons, or latent fingerprints and palmprints from a crime scene can be entered and searched against the database. This can provide potential new suspects if identifications are made as the result of an AFIS search. MVRCL’s AFIS also provides the capability to remotely search available Ohio BCI and FBI databases.
Latent prints can be left on porous, non-porous, or semi-porous surfaces that have been touched with bare skin. Non-porous items that are smooth, flat, and clean, like glass, plastic or metal, are generally good surfaces for latent print recovery. Porous items such as paper, cardboard boxes, and receipts are also suitable for processing. Semi-porous surfaces include Styrofoam and shiny coated cardboard or heavy papers. If there are ever questions about an item’s suitability or the best method for latent print processing or recovery, the Latent Print Section is available to answer questions or provide recommendations.
Standard Operating Procedures
I. Evidence Handling and Case Assignment
II. Automated Fingerprint Identification System
III. ACE-V Methodology and Case Documentation
VI. Report Writing
VII. Quality Assurance
Appendix A – Definitions and Abbreviations
Appendix B – Digital Imaging
Appendix C – Collection and preservation of potential bloodstains