Insect Artifacts Are More than Just Altered Bloodstains

Abstract

The bases for forensic entomology are that insects and their arthropod relatives can serve as evidence in criminal, medical and civil legal matters. However, some of the very same species that provide utility to legal investigations can also complicate crime scenes by distorting existing body fluid evidence (e.g., bloodstains, semen, saliva) and/or depositing artifacts derived from the insect alimentary canal at primary or secondary crime scenes. The insect contaminants are referred to as insect stains, artifacts, specks or spots, and are most commonly associated with human bloodstains. This review will discuss the different types of insect artifacts that have been described from crime scenes and laboratory experiments, as well as examine insect contaminates (non-blood based artifacts, transfer patterns, meconium, and larval fluids) that have received little research or case attention. Methods currently used for distinguishing insect stains from human body fluids will also be discussed and compared to presumptive tests used for identification of human body fluids. Since all available methods have severe limitations, areas of new research will be identified for the purpose of development of diagnostic techniques for detection of insect artifacts.

Distinction of Fly Artifacts from Human Blood using Immunodetection

“…This binding is in agreement with previous observations of pepsin-like activity detected in regurgitate and crop fluids of P. terraenovae (13). It also supports the contention that regurgitate stains are derived from expulsion of food from the foregut, with no contribution from the adult midgut (10,27).…”

“…terraenovae , following blood feeding, four types of artifacts (regurgitate, defecatory, translocation, and transfer patterns) are produced that met the definition of insect stain, yet none can be distinguished morphologically from human bloodstains in a consistent or reliable manner . These limitations have been reported for at least 6 other species of cyclorrhaphous Diptera ; Adult necrophagous flies can produce artifacts as a result of feeding on several types of fluids other than human blood (e.g., saliva, semen, vaginal fluids, and decomposition fluids), which yield artifacts that vary widely in terms of shape, color, and size, that vary based on the surface in which they are deposited, and that are indistinguishable from human body fluids based on appearance ; Contextual analysis does not overcome the limitations of visual analysis, especially when the insect stains lack tails and are intermixed with human body fluid stains, and/or the artifacts are of similar size to body fluid stains ; The artifacts of only 6 species from two families (Calliphoridae and Sarcophagidae) of necrophagous flies have been examined in any detail, and all are primarily laboratory‐based observations . Thus, it is difficult to come to any consensus on the typical classification of fly artifacts or accurate methods of detection of insect stains found at crime scenes. …”

Crime scene and body alterations caused by arthropods: implications in death investigation

“…Among these, 7 were case reports [13][14][15][16][17][18][19], 3 case series [6,20,21], 19 original articles [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], 4 were technical notes [41][42][43][44] and 8 were reviews [1,10,[45][46][47][48][49][50].…”

In-SilicoInvestigation of Luminol, Its Analogues and Improved Mechanism of Chemiluminescence for Blood Identification Beyond Forensics

“…melanogaster and few other insects provide insights to the degradation state of the body fluid in the crime scene (Leitch et al, 2018;Jiang andEdgar, 2011, Kulstein et al, 2010) and also serve as source of artifacts (Rivers and Geiman, 2017). The ZINC17023010 (compound 12) which is known as benzo[g]phthalazine-1,4 (2H,3H)-dione, was found to produce chemiluminescence by reaction with hydrogen peroxide in the presence of potassium hexacyanoferrate (III) in an alkaline medium, with low relative chemiluminescence intensities (RCI) than luminol and high relative fluorescence intensities (RFI) than luminol after the chemiluminescence reaction (Yoshida et al, 1999).…”