Zombie CSU (15 page)

Becka agrees. “Whether or not you find a fingerprint on an item depends on the amount of oil and water on the person’s hands, the item’s surface, the climate, and about a million other things. Contrary to TV, you don’t
always
find prints on this or that and you don’t
ever
find prints on this or that.”

Even so, science marches on and there have been several significant advances in fingerprinting over the last few decades. According to Becka, “The biggest advance is, of course, computerized database searching. I can mark the points of minutia in a latent print collected at the scene and the computer finds possible matches for me. This means I don’t have to search card files for matching prints and die of tedium. Note that the computer does not decide
if
someone is a match or not, it only summons the prints with the most similar pattern of points.”

One point of clarification:
fingerprint
is used somewhat loosely here—as it is in all pop culture. According to Martin Leadbetter, FFS RFP BA (Hons), international fingerprint expert and chairman of The Fingerprint Society, “‘Fingerprint’ is usually used to describe inked impressions taken for a specific use, e.g., recording prisoners’ fingerprints, elimination fingerprints, cadavers etc. The terms,
latent
,
latent mark
(or
mark
, as used in the UK) always refers to impressions found at crime scenes or on forensic exhibits.” He goes on to explain the different kinds of prints:

 


Rolled ten-print impression (U.S. and international terminology) sometimes referred to as inked impressions or inked fingerprints in the United Kingdom: This is an impression whereby ink has been placed onto the ridged skin of the fingertip and then subsequently rolled onto a ten-print card or form in order to record an exact image of the finger’s pattern and ridge detail. Upon the arrest of a suspected person, this procedure is repeated for each of the ten digits in order to produce a ten-print card.


 


 


Slap prints (or in the United Kingdom, plain impressions): Slap prints are also recorded on the ten-print card and are used to check that each of the rolled ten-prints has been taken in the correct order. The four fingers of each hand are inked by being placed flat on an inked surface and then placed simultaneously onto the ten-print card. The two thumbs are dealt with in the same manner. (As a general rule, the term
slap prints
is not used in the United Kingdom.)


 


 


Palm prints: These are inked impressions recorded the same as ten-prints.


 


 


Latent palm marks, palm marks: These are palm marks recovered from crime scenes or forensic exhibits.


 

As technology increases, the reliability of fingerprints also increases. “The data sharing between computer databases holding vast collections of fingerprints has only increased the realization that fingerprints remain totally unique,” he says. “With the rapid searching of fingerprint databases no instance of two impressions taken from different fingers, thumbs or palms have been recorded. All claims within academia and the media that fingerprints are unreliable or unsafe are purely unsubstantiated and in some instances, mischievous. It should also be remembered that when referring to fingerprints the same criteria also belong to palms, toes and soles. Furthermore, all 187 species of primate possess fingerprints and share the same pattern types with humans. All instances where it has been reported that ‘two people have the same fingerprints’ or an error in identification has occurred are the result of poor forensic work or worse, conspiracy to pervert the course of justice.”

According to Leadbetter, different people need to know different things about fingerprints. “If you are a juror, then you need total confidence in the fingerprint system of identification, its uniqueness and the integrity of the fingerprint experts. If you are a detective you will know that fingerprint evidence, provided it leads to useful evidence, is the very best evidence you can ever hope for. The overriding issue here, is that fingerprint evidence, due to its unrivalled uniqueness is still the most conclusive and infallible of all the forensic sciences.”

This need for unique perspective holds true for the process of fingerprint collection. “Jurors would need to have confidence in the scene examiner, as indeed would all the officers of the court,” says Leadbetter. “For the scene examiner it’s a matter of knowing where logically to look and to find those fingerprints which will later assist in proving guilt.”

Leadbetter tells of another recent development that is helping police in the United Kingdom and America: “There is also
Live-scan
. This is a process whereby arrestee’s finger and palm prints are recorded electronically without the need for ink and paper. Once recorded, Live-scanned prints may be sent electronically to the computer system. As
Live-scan
devices have built-in ‘aliveness’ sensors it would be intriguing to know whether prints could actually be captured from zombies.” And, he adds, “It is also possible to retrieve DNA from latent prints, although again this would not be possible from all latents due to the factors previously mentioned.”

Forensic consulting scientist George Schiro tells of another new technology on the rise: touch evidence. “DNA recovered from touched evidence has a great impact on the development and collection techniques associated with latent prints. In the past, if a smudged print was developed, then that smudge had no value. Today if a smudge is developed, this smudge could be swabbed using a sterile cotton swab and a solvent, usually sterile water, deionized water, or an ethanol solution. This swab can then be air dried and eventually analyzed for a DNA profile. Also, surfaces such as rough or textured surfaces, typically not as good for recovering identifiable prints are better suited for recovering identifiable DNA profiles. Of course, in collecting this DNA evidence, crime scene investigators must take added measures to reduce the potential of DNA cross contamination between samples collected.”

The Zombie Factor

On the topic of zombie fingerprints, Schiro says, “A person who had only recently died then became reanimated would probably leave an oil based print for only a few hours after death. After that, the oils would probably not be replenished and the skin would dry out. An investigator would be better off looking for prints based in something the zombie had touched (blood, body fat, etc.) prior to touching the surface. If the corpse has been dead for a while or is reanimated in an advanced state of decomposition, then it is highly unlikely that usable prints would be recovered.”

Zombies, whatever else they are, were people first. A large percentage of our population has had identifying information recorded. If our patient zero had ever been convicted of a crime, then his prints would be on record. Just as they would if he had been in the military, worked for any of the more highly classified organizations, been part of certain drug testing programs, been a government employee, held a driver’s license in certain states (such as in California, Georgia, etc.), been registered with any of the child-tracking services, and so on. Bottom line is that there are a lot of people registered in the various law enforcement and military fingerprint databases. Though not all of these databases are shared,
⁹
there is enough information out there that a hit from a collected print is fairly likely.

Beeka believes that this would help us find our zombie, providing he’s one of the millions who have been printed. “Prints are not deleted, usually, from a database if the person dies, so a dead person’s prints would most likely still be in the file. And if they indulge in gore a lot, they’d be leaving plenty of prints in blood.”

Schiro has a lot of confidence in the growing database of prints, and says, “Fingerprinting would most likely be helpful in identifying the living dead who were reanimated shortly after their death for two major reasons. The first is that the recently deceased would be less likely to have their prints removed from the AFIS system, if indeed their prints are even in the AFIS system. Only a small percentage of the population is actually in the AFIS system and this small percentage is comprised mostly of people who have been arrested and booked into jail. The second reason is that those zombies reanimated shortly after death would be more likely to leave behind an identifiable print.”

“The human body decomposes at varying speeds depending upon a myriad of factors,” Leadbetter says. “For example…is the body inside or outside? Is the temperature high or low? What is the humidity? Is it immersed in water? Has it been burnt? Has it been subject to any contaminants? How did it die? Is it skinny or obese? Now in
zomboid
terms this raises a very interesting question. Bearing in mind that the skin on the hands and feet is often the last part of the human tissue to decompose, it must really be asked how quickly did the zombie regain its
undeadness
? If this was fairly soon after natural death, it could be that hardly any fingerprint detail had decomposed. If however it was the reverse, then there may not be any detail at all. In either scenario, the factors listed above will have to be considered.”

Schiro concurs: “And what about a zombie in an advanced state of decomposition? That would complicate things.” According to Schiro: “At some point decompositional changes will render fingerprint analysis useless. How the decompositional changes affect the fingers depends on many factors including the environment the body was exposed to prior to reanimation. Bodies exposed to the environment are going to decompose at a more rapid rate than bodies that have been embalmed or refrigerated. Bodies found in water are going to decompose differently than bodies not found in water. Insect and animal activity on bodies exposed to the elements could also affect fingerprints. Depending on the environmental conditions, the extremities (fingers and toes) could dry out and wrinkle, rendering them useless for leaving behind identifiable prints. Bodies undergoing decompositional changes in water or in humid environments will tend to slough off the outer layers of skin. This would also make it difficult to recover prints from touched surfaces.”