Which of these forensic scientists would be especially helpful in examining the sneakers to see if the traveler was telling the truth?

a. Toxicologist, b. Xylotomist, c. Palynologist, d. Pedologist.

c. A palynologist to look for pollen grains on the sneakers and
d. A pedologist to examine the soil.
The purpose would be to determine if the soil and pollen matched the types found in the region where the robbery occurred.

A palynologist studies fossil and modern pollen grains, spores, and other acid-resistant microorganisms. Forensic palynology provides evidence, to establish or disprove links among people, places, and objects. If one knows the composition of the "pollen rain" for a given area, then one will know what pollen types should be found associated with items from that area.

In our fictional scenario the palynologist would have looked on the sneakers for pollen grains and other microorganisms that could have originated from the area of France where the robbery occurred. If material found could be identified as occurring exclusively in that region the evidence supporting the traveler's presence there would be very strong.

In the case of the crashed plane where pollen was found in the blocked fuel line, the pollen found was almost exclusively from plants that are insect pollinated (entomophilous). The investigators could think of no plausible scenario to explain how entomophilous pollen could be filtered from the air to the virtual exclusion of wind-pollinated types, which were abundant in the area. They hypothesized and later proved that the blockage was caused by nest building by leaf-cutter bees and occurred after the crash.

A pedologist studies soils and can identify the source of a soil sample by comparing it with samples of known origin. With detailed information about color, texture, particle sizes, minerals, oxides, organic matter, and microorganisms a pedologist (often with input from scientists from biological disciplines) can identify a soil sufficiently well to be able to prove its geographical origin. In the crashed plane case cited above, the plane burned as it crashed and the fact that soil found associated with the wrecked plane had not been burned was evidence that the soil too accumulated after the crash.