clandestine burials one

7/30/2019 Clandestine Burials ONE

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Clandestine_Burials_ONEWith careful excavation, a grave may reveal a wealth of information in addition to being the location of

a burial. This information may come from:

The body itself including its position, apparent trauma, the postmortem interval and indications of

secondary burials

The grave contents such as evidentiary items, and information related to initial location of the body,

seasonality and postmortem interval

And the grave itself including toolmarks, the minimum time since burial, evidentiary items, and

sequence of events of grave construction.

During the excavation we recommend the following records be kept in addition to your standard

evidence log and scene documents. Again, you can download the package of document files from this

slide.

Documents include:

A burial information sheet with the location of the scene, scene description, agency, personnel, datum

description and reference points, GPS coordinates, and datum height above surface.

Mapping and recovery log with descriptions, item numbers, and coordinates of all mapped items.

Photography log with image numbers, descriptions, and item numbers if applicable. Burial map, plan

view which is a scaled map of the excavation unit as viewed from above.

And Burial map, profile view which is a scaled map of the burial in profile.


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In preparing the site for excavation, evaluate the needs and limitations for the recovery. Consider such

things as personnel, equipment, warrants, weather, access, and the environment.

Secure the scene using the investigating agencys/agencies protocols such access, logs, and security.

Establish a restricted corridor of access into the scene and within the scene such as between the

excavation unit, the sifting area, and the evidence collection area. For instance this would prevent the

parking of a vehicle on a grave site as occurred in this scene.

Identify and mark the overall scene as well as the burial and excavation unit.

The excavation unit is a rectangular or square area surrounding your grave in which the excavation will

be conducted.

First, mark the boundaries of the grave with pin flags.

Before any excavation or mapping is done, evaluate the scene and determine the orientation, size, and

location for the excavation unit. The unit should be large enough to comfortably work in but small

enough to facilitate measurements from the edge of the unit to the grave.

Orientation is usually north/south and east/west. If this is not possible, orient the unit as needed and

record the compass bearing of the baseline when it is established.


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The datum is a known location in three-dimensional space that serves as a reference point for all

horizontal and vertical measurements taken at the site.

For small clandestine burials, the datum will typically be located at one of the corners of the excavation

unit. Ideally, the datum point will be higher than the rest of the excavation unit to facilitate vertical

measurements. Often the datum point will be the top of one of the corner stakes. Record the distance

from the datum point to the ground surface.

The datum is located by triangulation with two or more points that will not change over time such as a

utility pole, building corner, or mile marker. It may be necessary to use a semi permanent point such as

a large tree. The distance and bearing from the reference points to the datum must be recorded on your

form as well as a detailed description of the points.

Although GPS units appear quite accurate; the typical handheld units are not accurate enough to

produce a useable map of the burial scene.


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GPS coordinates are useful to locate the scene broadly and help to localize the unit datum. However,

permanent reference points should be used for precise datum location.

There are many methods (and opinions) that may be used to record the coordinates for the items

located within the excavation unit. The goal of all methods is to accurately record the relative positions

of all features and evidence encountered during the excavation.

Common, simple methods include: construction of a grid that overlays the excavation unit, two

reference lines, or X/Y axes, and triangulation from two fixed points.

If the unit is not large, using 2 perpendicular reference lines provides a balance between ease of use and

the accuracy of the coordinates recorded.

Once you have determined the unit dimensions, you will need to establish the baseline or x-axis.

From the datum stake, measure the predetermined distance and place a stake.

If the base line is not oriented to a cardinal direction (such as North South East or West), record the

bearing of the baseline FROM the datum on the data form. It is important to record the bearing from

the datum point in order to re-establish the unit. For example, you may be asked by the court in the

future to demonstrate the excavation during a trial or to return to the unit and search for additional

evidence.


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Establishing the Y axis or the perpendicular reference line for the unit is the next major step. The

simplest method is to construct a right triangle where the sides of the triangle are the sides of the unit.

A right triangle measuring 3x4 meters with a 5 meter hypotenuse works well for most single grave

situations.

With a base line of 4m, and using a hypotenuse of 5m and a Meridian (or y axis or perpendicular

reference line) of 3m would create a right angle .

To establish the perpendicular line, use two measuring tapes. Extend a tape the length of the meridian

(Y-axis) from the datum stake and extend the second tape the length of the hypotenuse from the other

end of the baseline. Where the two tapes intersect will be the position of the stake for the end of themeridian reference line (Y-axis).

Optionally, repeat the process to place the 4th stake.


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A unit of any size can be created by using a hypotenuse table or calculating the length of the hypotenuse

from the desired lengths of the sides of the excavation unit.


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A hypotenuse table can be an easy way to determine the length of the needed hypotenuse without

calculations.

For example, an excavation unit 3m by 4m in size would require a 5m hypotenuse.


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Next establish the plan view map of the excavation unit (or the map as would be viewed from above the

unit) using the form provided or graph paper. Your maps should include all of the recovered evidentiary

items, not only the human remains. Additionally, the map should include: case information, North

orientation, unit datum, reference lines and a scale.

The profile view map is similar to the plan view except that the datum height above surface must be

recorded and there is no north orientation. The mapping and recovery log and the photograph log

should also be started at this time.

Minor elevation changes can still be mapped using the same method by using taller stakes on the

downhill side or sides. Make sure, when measuring for your base line, that the measurement is

horizontal and use longer stakes as necessary to create level reference lines. Maintain a horizontal plane

when measuring for your meridian or Y axis stakes.


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With larger elevation changes, it may be impractical to extend the baseline across the entire excavation

unit. Establishing reference lines in this case is much more complex and we strongly recommend you get

expert help. Now the baseline will need to be stepped to accommodate the slope. Effectively we are

subdividing the excavation unit into two or more subunits.


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As you can see and read, this is a much more complex process and is why we strongly recommend you

seek expert help with a site on steep slopes.

A slightly more complex version of a two-axis system is the creation of a grid over the excavation unit.

Typically 1 meter by 1 meter squares. A grid is useful when the excavation unit is more complex, larger,

or in cases in which the entire unit will be excavated.

Advantages of a grid system include, greater mapping accuracy and control over the excavation process,

disadvantages include a more involved set-up process and a hindrance of movement within the unit.

Sweep the unit with a metal detector before beginning to remove surface cover.

Scraping from the edge toward the center of the unit with a sharpened square shovel, remove 2-3 cm

(or about an inch) of soil and vegetation from the unit. Record and map any evidentiary items.

Screen all soil and vegetation removed from the unit, noting the location of each bucket so that

recovered items can be associated with a location.


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By scraping in toward the grave, the disturbed soil of the grave tends to fall away from the undisturbed

grave wall.

If the grave edge is evident, excavation will be only within the grave so that the grave walls can be

inspected.

If the grave edge is not evident after the surface scrape, the entire unit will be excavated until the grave

edge is evident. At that point, excavation will continue within the grave only.

Note the difference in texture of the undisturbed soil surrounding the grave and the disturbed soil which

makes up the grave fill after 3 months.


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Attach your reference lines, making sure that the strings are tight since you will be measuring from them

throughout the excavation.

Attach a datum line that is long enough to reach across the excavation unit to the top of the datum

stake using a nail.

Measure the distance from the line to the ground surface at the base of the datum stake. Record this

measurement on your data sheets.

Attach a line level to the datum line and coil it at the base of the datum stake for later use.


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Three measurements, a description, and an item number that corresponds to a number on the map

must be recorded on the mapping and recovery form.

Pull the string from the datum stake to a point over the object or grave feature in question making sure

that the string is level using the line level.

Measure the vertical distance to the object, this will be the below datum measurement. If the vertical

distance is not great, a folding ruler or stiff tape measure may be used. For larger distances, use a plumb

bob to ensure that you are directly over the object.


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Measure the distance from the point above the object to each axis of the unit, maintaining a horizontal

plane.

The baseline (X-axis) distance is measured from the Meridian (Y-axis) to the point over the object.

The meridian (Y-axis) distance is measured from the baseline (X-axis) to the point over the object

Recording the coordinate measurements in the same order for all points mapped will prevent many

recording errors.


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Again, note the measurement of the depth from the datum point using a tape measure and reference

line; the x coordinate measured from the y axis; and y coordinate measured from the x axis.

Note also the use of three people, with two measuring and one recording the coordinates.


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The minimum grave features that must be mapped are the four corners of the burial cut and the floor of

the grave. If there are elevation changes or changes in the composition of the burial fill, these need to

be mapped also.

Map any items that may be evidentiary in nature. These may include ballistic items, coins, fabric, rope,

cigarette butts, and others.

Once the body is exposed, the minimum points for an articulated set of remains are: the skull,

shoulders, elbows, wrists, hips, knees, and ankles.

Mapping these points will allow for the future reconstruction on the bodys position within the grave.

If in doubt, mapping more points than needed is preferable to not mapping enough points.


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Mapping disarticulated remains is more complex, requiring more mapping points. For example, map

both ends of the long bones such as the femurs. This level of detail is important in that it may document

a secondary burial or a dismemberment of the remains prior to burial.


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Many agencies now have access to electronic total station mapping through their accident

reconstruction team, crime scene team or their city engineering department. The datum when using a

total station will be the location of the total station rather than a corner of the unit. Position the total

station so that the excavation unit is easily visible to the total station and record two permanent

reference points using the total station. It is best to mark and clear the excavation unit as you would if

constructing a grid or reference line system.

Coordinate information for the burial unit and mapped items will be collected electronically by the total

station eliminating the measurements made physically using a reference line or grid system. As a

precaution record the coordinates acquired by the total station on the log sheet in case your electron

data are lost.