Access Interval
Definition
Any period after death during which insects could not reach the body, whether through concealment, refrigeration, submersion, or wrapping. The access interval inflates the gap between true PMI and mPMI.
- Causes
- Concealment, refrigeration, submersion, wrapping
- Effect
- Delays insect colonization
- Consequence
- Widens gap between true PMI and mPMI
- Field
- Forensic entomology, PMI estimation
Common questions
Why does the access interval matter for PMI estimates?+
Entomological estimates measure how long insects have been developing (mPMI), not how long the body has been dead (PMI); an unaccounted access interval makes the mPMI an underestimate of the true PMI.
How do entomologists account for a possible access interval?+
Scene evidence such as wrapping, burial depth, or indoor placement is used to estimate how long colonization was delayed, and that estimate is added to the mPMI figure.
Does refrigeration always create an access interval?+
Only while it actually prevents insects from reaching the body; refrigeration that merely slows development after colonization has already begun affects growth rate rather than access.
Related terms
- Colonisation
- The event when gravid female blow flies (or other pioneer species) locate the body and deposit eggs or first-instar larvae. The entomological...
- Larval Age Method
- Estimating mPMI by identifying the oldest, most developed insect stage present, staging it against a developmental timeline corrected for local temperature, and...
- Minimum PMI (Period of Insect Activity)
- The elapsed time since the first insects colonised the body. Because access may have been delayed, this is a lower bound on...
- Postmortem Interval (PMI)
- The elapsed time since death. Entomological PMI estimation uses the developmental stage and known growth rates of insects colonising the body to...
- Succession Method
- Estimating elapsed time from the species assemblage on the body by matching it to a local succession sequence: a known ecological progression...