Forensic entomology and the relevance of MLT contributions

Borneo Scientific Meeting 2017 Riverside Majestic Hotel; Kuching, Sarawak, 26th-27th July, 2017

Nor Aliza Abdul Rahim Department of Paraclinical Sciences, Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak Introduction

Forensic science is the application of sciences such as physics, chemistry, biology, computer science and engineering to matters of law.

Forensic science facilitate investigators to understand Eg: blood spatter patterns (physics), the composition drugs and trace materials (chemistry) determine the identity of an unknown suspect (biology).

Physical evidences are analyzed to provide scientific based information for solving criminal cases. Branches of forensic science Forensic entomology: the science and study of and other related to legal investigations.

: involved utilization of insects at crime scene to help solve crime cases particularly involving death. Insects of forensic importance

Calliphoridae: blow flies

Sarcophagidae: flesh flies

Muscidae: house flies

Order: : butterflies

Order: Coleoptera: beetles Use of insects as evidence in solving crime

In order to analyze samples from crime scene, existing forensic database is crucial.

1. an established insect life cycle (duration for each species)

2. insect succession pattern at the localities

3. database of common decomposing insects at the localities

4. climate influence on the development of insects in the localities General Fly Life Cycle Decomposition process and insect succession

Upon death the body will undergo decomposition processes.

Fresh Bloated Active Advanced Dry remains decay decay

Fresh stage –enzymatic breakdown of cells and tissues Bloated stage- metabolic activity of bacteria produces gases causing swell and pressure pushes liquid out of orifices causing strong odors Active decay stage -liquefaction and disintegration of tissue and odor persist Advanced decay stage -decomposition rate decreases due to loss of mass Dry remains- only bones are left and no odor detected Decomposition process and insect succession Insects will colonize the decomposing body in a successional pattern. Theory of 8 waves (Megnin,1894): Eight waves of arthropods come in succession in chronological order on a corpse during decay. Insect Corpse/carcass condition Insects group wave First Few minutes after death blowflies, houseflies Second Corpse/carcass start to smell several genus of blowflies Third Fat fermentation beetles, butterflies Fourth Protein fermentation group of flies and beetles Fifth Ammonical fermentation houseflies, beetles Sixth Slightly aqueous tissue dust mites Seventh Dried tissues beetles, butterflies Eight Bones or dry remains beetles

dust mite carrion beetle butterfly Table 4.7: Insects species associated with each decomposition stage of rabbit carcasses at peat swamp forests. Order Family Species Kolej Kenanga, UNIMAS, Kota Samarahan Stages Fresh Bloated Active Advance Dry (Day1) (Day decay decay remains 2-3) (Day (Day 7) (Day8) 4-6) Diptera Calliphoridae Chrysomya megacephala - I, A I, A I, A - Chrysomya rufifacies - I, A I, A I, A - Chrysomya nigripes - - I, A - - Hemipyrellia liguriens - - A - - Chrysomya villeneuvi - - A - - Lucilia cuprina - - A - - Hypopygiopsis violacea - - I, A - - Muscidae Musca inferior - - A - - Musca sorbens - - A - - Musca domestica - - A A A Musca sp. - - I - - Ophyra spinigera - - A A - Sarcophagidae Sarcophaga sp. - A I, A - - Hymenoptera Formicidae Crematogaster sp. A A A A A Odontomachus sp A A A A - Odontoponera sp A A A - - Pheidologeton sp A A A - - Oeophylla smaradgina A A A A A Lepidoptera berenice akaba - - A A - Coleoptera Staphylinidae Unidentified - - A - - A – Adult I – Larva • Climate or environmental changes can affect the life cycle of insects. • Climatological data (rain, temperature and relative humidity) and carcass temperature are recorded as a reference to the duration of life cycle of insects. Use of insects to determine PMI

Information useful for forensic entomology investigation:

Age and species of insect collected (to determine post mortem interval time, PMI) Use of insects to determine PMI

Utilization of insects to determine PMI time is useful especially when under circumstances where pathologist can only give broad approximation.

Eg: bodies with extensive burns bodies with advance decomposition Roles of forensic entomologist

Before analysis can be conducted:

1. proper collection of specimen from dead bodies 2. preservation of insects 3. mounting of insects 4. identification of insects 5. proper storage of insects

All these need to be done with detailed and correct procedure. Collection and preservation of insects Eggs, larvae and pupae • collected from various parts and around corpse. • killed with warm water and preserved in vials with 70% alcohol. • processed for mounting on slides for identification. • some are reared in laboratory on pieces of corpse tissues for adult identification.

pupa maggots Collection and preservation of insects

Adults • collected using sweep nets • killed with chloroform or ethyl acetate using killing jar • transported in the killing jar to laboratory before pinning for identification.

Sweep net

Pinned adult flies Killing jar Task conducted by a trained police officer or forensic scientist Storage of insects specimen

• Insect specimens from crime scene must be kept in a properly locked compartment or safety cabinet.

• Proper storage is required because those insect specimens are of medico-legal importance and will be presented as evidence in court. Can a Medical Laboratory Technologist contribute in forensic entomology? Who are the Medical Laboratory Technologist (MLTs)?

• Also known as medical laboratory scientist (MLS) or clinical laboratory scientist (CLS).

• MLTs are known to have roles and specific skills in laboratory and hospital where they work with samples and perform various diagnoses. General roles of MLTs in hospitals

In hospital, MLTs assist physicians in diagnosis of diseases.

• Performs haematological, immunologic, histopathological, cytophatological, microscopic and bacteriological diagnostic analyses. • Handle sample from body fluids: blood, urine, sputum, stool, cerebrospinal fluid, peritoneal fluid, pericardial fluid etc. • Prepare tissue for microscopic examination by pathologists. • Help determine blood type. • Assist in medical research and analyses. • Operates and maintains sophisticated instruments and equipment. General roles of MLTs in universities.

In universities, MLTs roles are more towards teaching learning activities. They assist lecturers in

• Set up for practical classes • Prepare specimen for teaching • Purchasing disposables and small equipment • Keep up with equipment maintenance schedule • Assist in research laboratory for many disciplines: microbiology, biochemistry, physiology, pathology, parasitology, entomology and etc. • Assist in field works. Possible contribution of MLTs in forensic entomology?

Possible contributions of MLTs in universities: • field work and insect rearing • sample processing, mounting and storage • identification, photo taking and data entry

Possible contributions of MLTs in Forensic (Entomology) Unit in hospitals • insect collection and rearing • sample processing and mounting • identification, photo taking and data entry • specimen safekeeping • reporting

With proper training, MLTs can assist in forensic entomology investigations and contribute to expedite preparation of insect evidence for expert witness use.