|The postmortem interval (PMI) encompasses the period of time
from when an individual died to when the remains of that individual
are discovered, or simply put, how long someone has been dead .
The correct determination of the time of death is an important goal
in forensic medicine as well as any death scene investigation. Forensic
entomologists are often asked to estimate the PMI of decomposing
human, and at times animal, remains [2-5]. In some cases, this
arthropod-based estimation has been the most dependable when dealing
with remains decomposing for weeks or longer . PMI estimates
by forensic entomologists have primarily been based on arthropod
development and/or succession models on carrion. However, precision
and accuracy in such estimates may be limited. This limitation may be
due to several factors including; 1) a lack of “known” times of death for
individuals from past casework; 2) a paucity of validation studies for
development data of arthropods of forensic importance, and; 3) a need
for clarification of the abiotic and biotic variables that determine when
colonization occurs with respect to the actual time of death – a semantic
argument that influences the entomologist’s implied inference of a PMI
estimation. In many cases, estimates of time of arthropod colonization
are more in line with a minimum PMI.
|For many years, forensic entomologists often communicated
their ability to determine the actual PMI of a decedent . Recent
publications have revisited this concept and determined that estimating
a PMI based on calculating the time of arthropod colonization of
remains , also termed the post-colonization interval [8,9], can be
accurate [10,11]. These estimates represent the period of time from
colonization of the remains by arthropods to the discovery of the
remains. In most cases, this period more readily translates into a range encompassing the minimum PMI. However, we recognize that there
are instances when this range might include the actual time since death
or the implied PMI or even longer in cases of myiasis. We note here
that colonization date often does not necessarily agree with the date of
death in many investigations.
|Entomological life history data used to explain delays in
colonization have not been studied for all forensically relevant
species. In most instances, existing published information on factors
attributing to the variation associated with colonization and succession
patterns of arthropods on human (or vertebrate model) remains tends
to be qualitative, limited in scope, or anecdotal. Consequently, these
explanations offer little insight towards the precision or accuracy of
opinions offered regarding insect behavior (specifically Calliphoridae:
blow flies) and delayed colonization on human remains.
|We recommend the use of standardized protocols in research
examining arthropod succession on carrion because it is important
for understanding the variation associated with making PMI estimates
in criminal investigations reliant on entomological evidence. For
this paper, we reviewed a representative portion of the forensic
entomology literature to provide a clearer picture of the often obscure,
but inherent, variability in parameters recorded across studies. Our
goal was to assess the types of data and parameters reported from a
representative range of papers directly related to forensic entomology
using a common searchable database; an approach often used for
meta-analyses or attempts to make general inferences in a discipline
from readily accessible literature. It was not our intention to provide
a comprehensive statistical assessment of all papers related to forensic
entomology, as there will always be omissions with grey literature and
studies published in obscure or highly regional journals that are not
broadly distributed. Our second goal was to use this set of papers to
assess and describe the variability in data and methods reporting that
affects the ability for making broader inferences that can be applied
and defended in the discipline of forensic entomology. Based on these
results, we propose a unified standard operating procedure that would
allow for a more statistically rigorous analysis of these data within and
across studies as they relate to understanding variability associated with
arthropod succession and its use in PMI estimates. If implemented,
data accumulated across studies should lead to a better understanding
of the decomposition process, arthropod succession, and improve
the accuracy of PMI estimates with these data. It is our intention that
these suggestions will lead to PMI estimates based on entomological
evidence that meets the criteria for admission of scientific evidence and
related testimony (i.e., Daubert standard) [8,9] that addresses the 2009
NRC report .
|Standard Operating Procedure for Succession Research
|From published papers, we evaluated 13 criteria important for
repeatability of a study on arthropod succession on carrion. These
criteria were: 1) animal model, 2) time of actual death, 3) euthanasia
method, 4) storage method, 5) storage time, 6) time of removal from
storage to placement in the field, 7) time of day remains placed in the
field, 8) catalog of arthropods associated with the remains over time
9) time of initial insect contact, 10) time of initial colonization (i.e.
arthropod offspring located on the remains), 11) study site, 12) number
of carcass replicates, and 13) the months and season of study (Figure
1). Eleven criteria are presented in (Figure 1). The remaining two criteria,
animal model and number of replicates, were not included in Figure 1
as all papers provided some relevant information.
|In order to conduct this survey, the terms “forensic entomology”
and “succession” were used as key words in a literature search in the
Commonwealth Agricultural Bureau database as this database is a
source for the applied sciences. Approximately 75 articles representing
the breadth of peer-reviewed published research associated with
carrion and human decomposition spanning from the 1980s to the
present were reviewed for the above 13 criteria. Articles ranging
from the 1950s to the 1980s were added through a search of our files
in order to compensate for the potential bias of contemporary search
engines. This survey of the literature was not meant to be an exhaustive
assessment of carrion decomposition relevant to forensic entomology
that has been published. Rather, our goal was to evaluate a portion of
the literature that used both ‘forensic entomology’ and ‘succession’
within the content of the published paper to represent the trends in
research that had forensic entomological relevance. The survey was
meant to identify and address key aspects of data that are necessary to
perform more robust statistical analyses (e.g., meta-analysis) necessary
to generate larger generalizations about the biological, ecological and
evolutionary underpinnings of forensic entomology. Summaries of
the studies are presented in figure form in order to avoid identifying
authors and to more appropriately highlight the criterion of interest.
|In order to evaluate relationships of invertebrate taxa richness
with carcass type, size class and mass, we analyzed taxa richness from
40 published papers where the arthropod taxa lists were given for
vertebrate carcass decomposition experiments. Using these taxa lists
and the published paper as the replicate, we employed non-parametric
Kruskal-Wallis tests to statistically evaluate taxa richness differences
among carcass types (e.g., swine, bear, and rat) and size classes (e.g.,
groupings by 10 kg intervals) (Figure 2). Linear regression also was
used to test for the relationship of taxa richness with mean carcass
mass (Figure 3). For the remaining criteria and potential relationships
among criteria, there was inadequate information reported from the
literature, and thus, no statistical analyses were performed.
|A large diversity of animal species has been used in decomposition
studies (Figure 4). These animal models included, but were not limited
to, chickens, Gallus gallus domesticus (Linnaeus) , lab mice, Mu musculus Linnaeus , sheep, Ovis aries Linnaeus , domesticated
cats, Felis catus (Linnaeus) , and monkeys, for instance
Cercopithecoidea sp and Presbytis cristata (Horsfield) . However,
previous investigators have primarily used the domestic pig, Sus scrofa,
as a research model for forensic entomology [18-25] which has been
demonstrated in a limited sense to be a suitable analog for human
subjects in forensic entomology as the arthropod faunal succession
is similar between both species . Additional research comparing
human to pig decomposition is still needed as the previous study cited is
from a single location in Tennessee and only contained a single human
replicate. Other studies, such as Hewadikaram and Goff , have
suggested that the taxa recovered from carcasses of varying sizes do
not differ . However, several studies do indicate that documented
arthropod taxa vary depending on the species of animal used in the
study. Published studies on rabbit [28-32] and rat carrion [33-36] show
a general trend of less arthropod diversity than on pig carcasses. This
conflicted finding could be compounded by carcass size , amount
of hair on the body, and insufficient published data did not allow for
a direct comparison between rats, rabbits, and fetal pigs or adult pig
carcasses. Preliminary decomposition studies have been conducted on
wildlife carcasses (black bear, Euarctos americannus Gray; white-tailed
deer Odocoileus virginianus Zimmerman; American alligator, Alligator
mississippiensis Daudin; and domestic pig) and determined that alligator
carcasses hosted less diversity than either of the three mammal species
. From such work, it appears evident that at least some arthropods
may exhibit a carrion preference. Consequently, future research studies
should record information such as animal species, size, and sex. We
note two explanations for such variation in diversity. Such preferences
may exist because of developmental differences as noted by Clark et al.
 in which Lucilia sericata (Meigen), (Diptera: Calliphoridae) larvae grew much faster on pork than beef. An alternative explanation for
such preferences may be due to different desiccation rates for exposed
tissue, which may not be relevant to decomposition on carrion .
In many instances, significant differences in taxa and rate of biomass
removal did exist between varying habitats [41-44]. Carcass placement
studies have compared placement on ground , hanging , burned
carrion , and sun vs. shade exposure , and noted differences in
the arthropod colonization patterns and carcass decomposition rate.
|Time of Death
|The time of death offered by investigators is based on quantitative,
as well as qualitative data obtained through the examination of the
remains, recovery site, as well as information obtained by others
involved in the investigation. The term “time of death” and PMI are
often used inter-changeably in the literature. However, it is imperative
that researchers not mix up these terms as they have different meanings.
|We suggest that caution should be used when using these terms
to describe the data collected during arthropod succession studies.
Of the 75 papers reviewed, the actual time of death (Figure 5) was
quantitatively (i.e., an actual time) recorded in only three studies
[20,23,47] and qualitatively (i.e., a general time frame such as morning
or evening) in another three [48-50]. These studies represent <10% of
the studies reviewed. Therefore, relating time of colonization to the
actual time of death by the authors or those using these data is not
recommended. In order to gain a better, and statistically relevant,
predictive ability, we recommend that researchers record the specific
time of death as such information could lead to a better understanding
of the variation between death and actual colonization of the remains.
|Storage Method, Storage Time, and Transition Period from Storage to Field for Animal Remains
|Storage of animals used in decomposition studies was highly
variable (Figure 6). Methods varied from placement of the remains
in a freezer [41,51,52] to nothing at all [53-55]. In many instances,
locating a suitable number of animals (Figure 7) to meet replication
requirements for a strong experimental design was difficult. Typically,
researchers are often required to purchase and store animals until
the targeted number of specimens has been reached to conduct an
experiment. In the literature examined, this hurdle was best exemplified by those individuals examining arthropod succession on endangered
or protected animals [49,56].
|In many instances, the method of euthanasia (Figure 8) was
highly variable. Many data, such as the methods employed to store
the animals (Figure 6), time stored (Figure 9), or the time from the
removal of the remains from the storage unit to their placement in the
field (Figure 10) were rarely recorded. We provide several examples to illustrate this position. Tomberlin and Adler  did not freeze their
euthanized animals but placed them in plastic bags and transported
them to the field; requiring additional time prior to commencing with
the experiment. Van Laerhoven and Anderson  used fresh carcasses
as well, but also experienced a delay of five to eight hours from death to
placement in the field. Schoenly et al.  utilized a single human and
multiple porcine corpses in their study and indicated a minimum of 48
h storage at 4°C. Tessmer et al.  used longhorn chickens euthanized
with CO2 and stored for two days, and Michaud and Moreau 
used freshly euthanized pig carcasses that were double bagged. Both
studies experienced a two hour delay from death of their animals to
their placement in the field, while Patrican and Vaidyanathan 
utilized CO2 and sodium pentobarbital to euthanize rats and needed
one to four hours post euthanization to transfer them to the field.
Micozzi  used Wistar rats euthanized with cervical dislocation and
stored them in a freezer for four weeks, while Reed  used canines
euthanized with strychnine and freshly placed in the field. In both
cases, the authors needed eight to nine hours respectively to move
their animals to the field. In contrast to these shorter time intervals, Tullis and Goff  used pig carcasses euthanized with undisclosed
methods and stored in a freezer. The remains were allowed to thaw for
16 h prior to moving them to the field. Archer and Elgar  used fresh
stillborn piglets and in other instances used piglets that had been stored
in a freezer for an undisclosed period [63,64]. In all of these cases, if
the authors used arthropods to estimate a PMI they would have been
grossly inaccurate in such estimates because of the amount of time in
storage. An analogy is if a frozen mastodon was thawed and exposed to
carrion arthropods, the PIA would accurately reflect how long insects
had been present on the remains, but if a PMI would be estimated using
the same insect evidence, it would be grossly inaccurate by potentially
thousands of years.
|Previous studies that recorded amount of time in storage and time
from removal from storage, or euthanization, to the field (Figures
7-10) represented approximately 15% of the total studies examined.
Consequently, there is a need for more standardized methodologies
relative to storage method, time and transition periods from lab to field
in order to allow for greater accountability of the variation associated
with actual time of death, placement in the field, and when arthropod
colonization takes place. Such data should allow forensic entomologists
to conduct more detailed meta-analyses of arthropod succession
patterns leading to a greater understanding of the variability in the time
from death to colonization. However, we recognize that the initiation
of some studies [26,38] has revolved around the availability of remains
and absence or limited proper storage facilities and, under these
circumstances, consistency in storage method and initiation of a study
will vary. With future research, by simply recording this information
a better understanding of the effects of storage on the decomposition
and arthropod succession process as well as the parameters guiding the
application of these data in investigations may be possible.
|Based on the review of these publications, we realize that the actual
time of death as it relates to time the remains spend in storage prior
to placement in the field can vary greatly depending on the study. For
example, Watson and Carlton  used a single black bear that had
been struck and killed by an automobile the night prior to the initiation
of their study. Initial arthropod contact on the bear carcass occurred 15
min after placement of the carcass in the field the next day; however,
actual colonization was not noted until day two of the study. With
the Watson and Carlton  study, time of death was qualitatively
recorded (i.e. night before study) as well as colonization (day two of
study). The purpose of reviewing this publication was to demonstrate
the need for more quantitative approaches (i.e. actual times need to be
recorded) in forensic entomology research.
|Time of Day Study Initiated
|Sixteen of the 75 reviewed studies indicated the time when the
remains were placed in the field (Figure 11). Times were not consistent
and ranged from 0600  until 2200 h . In contrast, some
provided qualitative descriptions of the initiation time. For examples,
Waston et al.  placed their carcasses in the field just before dawn,
while Schoenly et al.  placed their carcasses in the field the evening
|The time of day the body is exposed to arthropod activity can result
in differences in species abundance and type attracted to the remains
.During the summer months in Florida, Chrysomya megacephala
(Fabricius) (Diptera: Calliphoridae) is typically the first blow fly
species to arrive at decomposing remains in the early morning hours and is often the last to depart carcasses in the evening, sometimes well
after sunset (Byrd, pers. observation). Because time of day influences
arthropod activity and colonization patterns [66,67], it can be expected
that succession patterns would be influenced by the primary species
that colonize the remains . Initial colonization by one blow fly
species could result in a distinct succession pattern than that generated
for another species. For example, Phormia regina (Meigen) and
Chrysomya rufifacies Macquart (Diptera: Calliphoridae) are suspected
by some to be delayed colonizers, while L. sericata is suspected to be
an early colonizer . However, the time to colonization can vary
depending on the presence of larvae from other blow fly species on
a carcass. The presence of L. sericata offspring on a carcass decreases
the time to colonization by P. regina . The same may be true for C.
rufifacies with time to colonization being dependent on the presence/
absence of Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae)
which is a prey item for this species [70-72]. These assumptions are
currently under debate because it is not for certain that these events
occur and if such information should be taken into account when
estimating the PIA .
|The periodicity of arthropod activity certainly has implications
to forensic entomology. For instance, the possibility of nocturnal
oviposition has been shown to have profound implications on the
extrapolation of the post-colonization interval to estimate the PMI.
One of the first studies conducted on nocturnal oviposition by blow
flies undoubtedly confirmed that oviposition by L. sericata can occur
in dark places during the day, and even during night . Blow fly
oviposition occurred on one of six replicate swine carcasses almost two
hours after sunset, under heavy cloud cover and during the rain in a
forested habitat surrounded by agricultural fields in southwest Ohio
(ME Benbow, personal observation). Earlier studies demonstrated
that nocturnal oviposition may be possible and that some flies may be
facultative, not obligate heliophiles. Greenberg  placed bait on the
ground under bushes that allowed for the possibility that flies, already
at roost on the bushes, to simply walk to the bait without having to take
flight. However, in Greenberg , street lights might have provided
enough light to allow nocturnal colonization to occur. The question
of flies laying eggs on a body after dark having been attracted from
a distance requiring flight has yet to be definitively answered. For
example, in one study, field experiments conducted by Singh and
Bharti , demonstrated that Calliphora vicina Robineau-Desvoidy
(Diptera: Calliphoridae), C. megacephala, and C. rufifacies would
oviposit during the night (light intensity 0.6-0.8 lx). In a second case,
a study by Baldridge et al.  showed that necrophilous flies were
present on the bait up to 50 min post-sunset, and activity did not
resume until after 0600 h the following day. This study found that
nocturnal oviposition did not occur except in one instance within 20
min post-sunset. Of great interest to forensic entomologists are the
published studies [25,76] which included a field component and an
indoor study as they allowed for field research to be validated under
controlled conditions. These two studies concluded that nocturnal
oviposition did not occur under field conditions; however, nocturnal
oviposition by L. sericata did occur indoors under complete darkness
in two of the six trials. These studies supported the original conclusion
of Greenberg  that oviposition during darkness may occur when,
in the Greenberg  case, bait is close enough to gravid females not
requiring them to take flight to reach the bait source. Another study
 indicated that instances of nocturnal oviposition did not alter
entomologically-based estimations of the post-colonization interval
because any such activity would be delayed and result in limited
numbers of larvae. Another recent study  found that flies did
not oviposit under nocturnal conditions in the field. This study also
found that oviposition did not occur under complete darkness in a
laboratory setting for bait placed on the ground or hanging. This was in
contrast to the positive findings of the 2008 study by Amendt . An
interesting component of the Zurawski  study was that adult flies
launched into the air under complete darkness in a laboratory did not
fly. Clearly, the limited nocturnal oviposition studies that do exist in
the literature are contradictory, and forensic entomologists must take
this lack of congruity into account when evaluating this possibility in
an estimation of the PMI.
|Time of Initial Arthropod Contact
|Tomberlin et al.  have defined the time from death to initial
arthropod contact as the exposure phase in the decomposition process.
While in the past this phase (i.e., time from death to initial arthropod
contact) might seem trivial in terms of time, events occurring during this period may be critical for truly estimating the minimum PMI. In
some instances where a death occurs at the site in question, this phase is
essential for estimating the actual time of death. Of the studies reviewed,
33% provided information regarding initial arthropod contact with the
remains (Figure 12). In most cases, these publications focused on the
arrival of blow flies. With this in mind, it should be noted that the time
of initial arthropod contact can vary depending on the arthropod being
studied. Even with blow flies, their arrival to carrion remains can vary
from seconds , to minutes , or days . Unfortunately, at this
time, a true appreciation of the variation surrounding arrival patterns
and the regulating variables is limited in the literature.
|In many cases, remains are discovered either prior to colonization
or well after the majority of the soft tissue has been removed by
arthropods competing for these resources. In the latter case, abiotic
factors, such as temperature, can shift from conditions suitable for
arthropod activity to unsuitable. This shift can be arthropod-specific
with the temperature gradient being partitioned into various ranges
where only specific arthropods are active. Consequently, arthropods
that arrive during one temperature range may be killed prior to
oviposition when the temperature shifts, and their remains left on the
decomposing resource. Understanding the delay from the moment of
death to arrival of arthropods, such as in the case previously described,
could become essential for estimating a minimum time of exposure or
death for the individual in question, and the dead arthropods located
on the remains might be the only evidence harboring this information.
|Time of Initial Colonization
|A key component in estimating a minimum PMI is being able to
estimate the elapsed time from death to colonization. While this time
interval would seem obvious, it has not been a point of emphasis in past
decomposition studies. Approximately 20% of the studies reviewed
recorded the time this event occurred (Figure 13). However, only
a few recorded the actual, or a retrievable estimate, of time that the
studied was initiated [23,25,38,48,65]. Consequently, the context of the
significance of this event cannot be translated and forces researchers
to rely on anecdotal information for interpreting decomposition related events. Such an approach might prove difficult for forensic
entomologists attempting to meet the Daubert standard [8,9] and NRC
|Depending on the study and the arthropod group targeted, 96%
of the studies recorded detailed information  related to adult and
immature arthropods arriving and colonizing the remains. For many of
these studies, blow flies were the primary focus of the study. However,
studies cataloging as much diversity associated with arthropod faunal
succession have been conducted. Payne [51,81-83] amassed the most
comprehensive collection of arthropods associated with decaying
remains. Payne’s research demonstrated the diversity of community
assemblages that occurred on remains and that there were many
opportunities available for research on targeted groups, such as beetles
, parasitoids , and acarids .
|Arthropod succession studies are limited to specific regions of the
world. Based on a literature review in 2004 , researchers from 22
countries conducted succession studies (Figure 14). The six most active countries, in descending order, were the United States (18%), France
(13%), Italy (6%), Australia (6%), Germany (3%), and Canada (3%).
Based on results from 2009, those values shifted to the United States
(9%), Australia (8%), France (5%), Germany (4%), Italy (2%), and
Canada (2%) (Tomberlin, unpubl. data). Within the United States from
1999 through 2003, research had been conducted in approximately
18 states including the District of Columbia. Consequently, many
regions of the United States are still in need of baseline data regarding
arthropod succession on carrion. What this means is that forensic
entomologists are often applying data from one region to another with
the hope that they are similar and allow for accurate PMI estimates to
be made, something that could prove difficult to defend in a court of
law. Future studies should record the location type (i.e., field or forest),
shade cover, and plant diversity. Recording the latitude and longitude
coordinates would be specific and allow the exact location of such sites
to be determined in the future if needed.
|These analyses indicate a tremendous amount of diversity in
forensic-related succession studies around the world. However, the
number of studies examining the succession of arthropods on carrion
is limited. Furthermore, the lack of information regarding actual time
of death and placement of the remains in a natural setting limits our
ability to determine delays in colonization pattern. To exacerbate this
issue, information related to time of initial arthropod contact and
colonization was limited. Approximately 43% of the articles indicated
some period of initial insect contact with the remains. Time intervals
were highly variable demonstrating the tremendous amount of
variation that may exist for such an event. Some intervals included 30 s
, five minutes , three hours , one day , and within one
to two days .
|Some abiotic variables, such as wind, rain, cold weather,
and environmental factors (i.e. water or soil) are known to delay
colonization. However, the variation in delayed contact within a single
ecosystem, much less within or between countries, is not known.
Another major issue was the reliance on qualitative terms to describe
the time of insect arrival at a carrion source [16,17,20,41,50,79,89]
which prevents accurate assessments and comparisons of previous
studies as the definition of these terms is dependent on the researcher
|The same trend observed for time of initial arthropod contact
with remains was also prevalent when describing initial arthropod
colonization. Some studies used specific measures, such as within one
hour , within three hours , and three days after placement .
Time of colonization is a vital observation for describing the ecological
processes occurring and its use in forensic entomological literature
when estimating a portion of the PIA, and thus the PMI. Furthermore,
these data can be used to validate published developmental data sets
for a given location.
|Period of Study
|Our review of the literature indicated that decomposition studies
have been conducted throughout the calendar year. As expected, a
majority of the studies occurred during the warmer months of the
year; however, arthropod colonization and succession during the
cooler months have been examined to a lesser extent (Figure 15).
But, if one were to step back and examine the total number of studies
examining decomposition ecology as it relates to arthropod succession
and location, we are just now beginning to understand the variations surrounding arthropod diversity and succession on carrion. While
some would view this as a hurdle, we view it as an opportunity.
|Bear and deer carcass invertebrate communities presented the
greatest number of arthropod taxa when compared to other carcass
model types (Figure 16) ; however, there was no significant
difference among carcass types which could be due to low replicates
(Figure 7) for each animal type being used in the study. Similarly,
there were no significant differences in taxa richness among carcass
size classes, but those between 30-40 kg and> 50 kg harbored about
10 more taxa on average compared to the other size classes. Lastly,
among previous studies examined, there was not a significant linear
relationship with mean carcass mass and taxa richness indicating
a large amount of variation both within and between studies of
vertebrate carcass decomposition. These results, collectively, indicate
the large degree of variation of invertebrate communities associated
with vertebrate decomposition.
|We recognize our study is not an exhaustive review of forensic
entomology literature examining arthropod succession on carrion;
however, our review represented the predominate literature related to
forensic entomology research from a searchable database supplemented
by older literature from four active researchers in the field. This review
identified important criteria necessary for future replication of studies
that are commonly, or not commonly, recorded in many cases. It also demonstrated that current studies represent a patchwork of necessary
data for more in depth comparisons of studies across ecosystems or for
pooling data for more far reaching conclusions regarding variability in
decomposition of carrion by arthropods.
|We suggest that future research examining arthropod succession
on decomposing remains include the following information; 1) animal
model, 2) time of actual death, 3) euthanasia method, 4) storage method,
5) storage time, 6) time from removal from storage to placement
in the field, 7) time of day remains placed in the field, 8) catalog of
arthropods associated with remains over time 9) time of initial insect
contact, 10) time of initial colonization (i.e. arthropod offspring located
on the remains), 11) study site, 12) replicate information, and 13)
months of study. By doing so, appropriate meta-analytical techniques
could elucidate a better understanding of the variation that may exist
in natural systems. Accordingly, an understanding of such variation
could allow for better predictions of the post-colonization interval
and potentially the amount of time between the moment of death and
insect colonization. In the end, understanding this variation will lead
forensic entomologists closer to providing estimates of a true PMI.
Furthermore, by understanding the variation and potential error rate
associated with the estimates provided by forensic entomologists,
the science becomes more in line with the basic sciences meeting the
recommendations provided by the National Research Council  and
the Daubert Standard which govern our courtrooms.
|The motivation for this research was not to criticize past research but to
develop a standard operating procedure for collecting valuable data typically
overlooked in decomposition research. Accounting for such information could lead
to future meta-analyses that provides a better understanding of the decomposition
process and potentially lead to increasing accuracy with predicting death of an
individual based on entomological evidence.
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