NCJ Number
205145
Journal
Journal of Forensic Sciences Volume: 49 Issue: 2 Dated: March 2004 Pages: 337-340
Date Published
March 2004
Length
4 pages
Annotation
This study examined whether it is possible to analyze human microsatellite DNA found in the digestive tract of necrophagous larvae that fed on decomposing bodies.
Abstract
Insect larvae provide valuable forensic information about corpses, including postmortem interval (PMI) estimations. Larvae found on decomposing bodies is collected and analyzed for stage of growth, thereby allowing estimations for the likely time of death; information which is valuable in criminal investigations. In some cases, it may be necessary to prove the association of fly larvae to a particular corpse. The current study analyzed the crop contents of maggots found on 13 human corpses with varying PMI’s as estimated by police investigations. The crop contents were subjected to both STR typing and hypervariable region(HVR) genetic analysis to allow for comparisons. Tissue samples from all the corpses were also collected and analyzed. DNA extraction involved the standard phenolchloroform extraction and ethanol precipitation. Additionally, species-specific DNA analysis was tested using DNA samples from the crop contents of other maggots which had fed on pig carcass. Results revealed complete STR profiles on seven of the cases. Two of the cases obtained incomplete sets of alleles and in the additional four cases, STR typing was unsuccessful. HVR analysis provided successful results in 12 of the 13 cases. The species-specific DNA analysis showed that identification of the host species, in this case a pig, can be achieved through analysis of the cytochrome b gene. Length of time in storage and length of PMI up to 16 weeks appeared to have no impact on the results. Future research should focus on establishing the amount of time during which STR typing of crop extracts can be successful after the maggot has left the corpse. Tables, figures, references