By examining crime scene insects near or in wounds on a corpse, a forensic entomologist can usually distinguish which wounds occurred before or after the victim's death.
Insects on Wounds Inflicted Prior to the Victim's Death:
When the heart is still beating, scratches, stab wounds, or bullet entries and exits will all bleed. Fresh, wet blood attracts necrophagous insects. Insects will begin to feed and lay eggs in these open wounds, which provide them additional points of entry into the body.
Insects on Wounds Inflicted After the Victim's Death:
Postmortem wounds, on the other hand, tend not to bleed and often remain dry and clean. Insects are much less likely to enter the body through wounds delivered after the heart stopped beating.
How a Forensic Entomologist Interprets Insects on a Wound :
If a wound shows evidence of early and active infestation, the forensic entomologist may report this as an antemortem wound. A wound absent of maggots or other necrophagous insects is most likely a postmortem wound.
