forensics

KN, p. 216 “Crime Scene at the Beach”

 

 

A recent vacation week took us to the beach and we were lucky enough to rent a cottage right on the ocean. What a pleasure to wake up to seagulls calling to each other as they found breakfast on the incoming surf at the edge of the broad expanse of sand. Morning coffee was extra special as we breathed in the sea air and planned the day ahead.

 

Aside from all the great sunsets, fabulous seafood restaurants, and much-needed relaxation, we found time to chat about fictional bodies and where to find them.

 

TV shows and movies feature their share of corpses that have washed up on the rocks lining the shores of lakes, bays, or oceans. Any crime scene at water’s edge has its own challenges for the CSI techs processing the area for evidence, and our vacation spot highlighted a few.

 

Consider footprints on the sand:

 

 

 

 


This print had been fully visible until a wave washed it partially into oblivion.

 

 


Sneaker treads next to the barefoot print, showed the traffic on the dry part of the beach just a few feet closer to the dune.

 

 

 

 

 

There was more than one kind of sneaker tread to be seen.

 

 

The sneaker and shoe companies have data bases going back several years indicating the treads and styles of the various shoes they have manufactured. A search warrant or a friendly conversation with the people at the companies will reveal specialty editions of their footwear and the year they were produced. Matching the footwear to the prints on the beach can narrow the suspect list – helpful if the culprit remained in the area and the sneaker was an unusual brand.

 

Consider the tire tracks:

 

 

A windy afternoon caused this tire tread to lose its definition.

 

 

 

 

 

 

 

 

This new tire tread was just ten feet away from the footprints.

 

 

 

 

 

 

 

 

 

 

 

 

 

Beach bikes were in use as well. I didn’t have a ruler with me, so Sheila donated her sandal. This gives you some perspective of the width of the tread, essential in determining the type of vehicles near the ‘scene of the crime.’

 

 

 

Tire companies have data bases as well, and make their information available to law enforcement officers when needed. CSI techs take photos of the various treads for later ID and if needed, make casts of the footwear prints. Read “Is that your footprint?” here.

 

All three vehicle treads were within 20 feet of each other, along with all the footwear prints seen here – and it wasn’t high season yet, when a greater variety of cars, dune buggies, bikes, and shoes would be around.

 

Any crime scene in such a well-traveled place means it will be tough to find the killer. Nature washes or blows away the evidence and the crime scene is compromised by all the foot and vehicle traffic.  

 

Law enforcement officers have to hope for witnesses to the dastardly deed.

 

We turned our attention to the places to hide the body:

 

 

 

This lovely walkway leading from the cottage to the dunes gave access to an area that looked suitable for body stashing. Except that it wasn’t really all that great for anything covert. Three houses near ours had direct line of sight to that walkway, and all had overhead lights strung along their own paths to the beach.

 

Each of the other houses had three floors – ours was the smallest of the group.  That meant that anyone looking out at the ocean could also see anyone dragging a body out to the beach grass next to/under the boards.

 

 

 

 

 

 

 

But, let’s say that nobody is looking out the window. While it is illegal to dig up the beach grass in the dunes because of erosion programs in most oceanside communities, a killer would have no such concerns. BUT, that Beach Grass (actual name is American Beach Grass) is tough. It’s meant to be, so that it holds the sand in place during stormy weather. It would not be practical or at all speedy to dig a hole in a grass-covered dune in order to hide the body.

 

Maybe that’s why so many bodies in the TV movies are dumped elsewhere and merely wash up on the beach. Then the writers don’t have to worry about how to hide the body at the scene of the crime.

 

 

Photo credits: Patti Phillips at the North Carolina OBX.

 

 

 

 

KN, p. 142 “CSI Techs – What is that smell?”

 

Last week’s article about what Crime Scene Techs really do can be read here.

 

Warning: parts of this article are extremely descriptive about the work of a CSI at a murder scene.

 

A Crime Scene Investigator (also known as an Evidence Recovery Technician) is a forensic specialist. A well-trained, experienced CSI tech has an organized plan of action when processing a crime scene. Most go through extensive training, if not in the classroom, then in the field while working with seasoned law enforcement officers, before being allowed to work solo. They study how to recognize evidence, how to document the process and the proper way to prioritize, recover, handle, and package that evidence at the crime scene.

 

Challenges

Some of the TV shows and movies touch on the challenges in the job of a CSI, but generally the scriptwriters try not to gross out the viewing audience.

 

Occasionally, the collection of the evidence requires a strong stomach. If the CSI works a homicide or accidental death scene, they will likely be dealing with strong odors.  Although air/water temperature may affect the rate of decomposition, a dead body begins to stink fairly quickly. Think rotting meat. CSIs have various ways of dealing with the odors. Some apply Vicks under their noses, some use medical masks, but some just get used to it.

In case you were wondering:  A former CSI told me that the Tyvek suits we see at crime scenes during British TV shows, work very well to keep unwanted fibers and DNA samples away from the scene, but do not block the odors at all.

 

Sometimes, bodies are dumped in the water, and that affects the rate of decay. The condition of the body recovered from water is a surprise to most law enforcement officers the first time they see it. Unless recovered within the first day or so, the skin and muscle begin to change at such a rate as to become almost unrecognizable for what they are. Special bags are needed to contain the remains while bodies are removed from lakes or ponds. The bags have holes in the sides to allow the water to escape, without losing the body parts.

 

The condition of a body recovered in the heat can be a challenge on several levels. The body swells up and can pop if not handled correctly. In ‘cold cases,’ where the body has been sitting outside for months, perhaps only the skeleton will remain, requiring identification through dental records or bits of clothing still attached to the bones.

 

Homicide and some accident scenes can be bloody. It’s fair to say that most law enforcement personnel are deeply affected by the surprising amount of blood found at a murder scene or a particularly horrific accident scene. It’s tough to get used to that part of the job, however much experience you’ve had. But, it’s important to stay detached while collecting the evidence, taking the blood spatter photographs, and detailing the information, so that the victims can be represented properly in court.

On rare occasion, gloves and protective clothing that a CSI wears can rip or tear, exposing the CSI to possible infection or disease.

 

Stress and even grief can be factors that might affect the CSIs or ERTs. Working on fraudulent documents or stolen property is worlds away from dealing with dead bodies. Some larger departments offer (and even require) grief/stress counseling after emotionally tough cases, but the smaller departments just don’t have the resources for that. Imagine waking up night after night, reliving a crime scene in nightmares. In cases involving multiple deaths or children, the stress level can be especially high.

 

Rewards

So, with all the possible negatives/challenges in the job of a CSI, why would anybody do it?

Because of the result. A job well done helps to put the bad guys away.

 

Training

The job of a CSI changes based on geographic location and the needs of the department. Some towns have no budget for a full-time CSI and hand off cases requiring special evidence collection to County or State personnel. In general, big cities have more homicides and other crimes, so require full-time CSIs.  In small towns, the Police Chief or Police Officer might do the investigating, collection and analysis of the evidence.

 

With those factors in mind, training requirements vary from region to region and from decade to decade. Some departments require college degrees (i.e. Criminal Justice or Forensics) for their law enforcement personnel, with the understanding that specialized training (i.e. photography, computers, etc) might be required as cases come up.

 

Then after getting hired, the CSI tech will spend some time as an apprentice to a more experienced person – think the ‘probies’ on NCIS, the TV show.

 

One realistic test to see if possible candidates are really suited to the job of CSI at a murder or accident scene is to have them visit a morgue or an ER. If they get through a busy, bloody night at an ER, they might be able to work in Homicide.

 

If not, I’m told that there is lots of work in Forensic Accounting and CyberCrimes for CSIs, that does not involve blood or body parts.

 

*Photos by Patti Phillips

 

 

 

KN, p. 76 “Save the duct tape and glue the dashboard!”

 

Criminals that tie their victims up during the commission of a crime frequently use duct tape for the job. That duct tape is almost always full of prints that get embedded into the tape. It’s practically impossible to manipulate and tear the tape while wearing gloves (I tried this once and the gloves got so stuck to the tape that I threw the resulting mess away), so the crook leaves prints while unrolling and tearing the tape. Even if he has wiped the smooth surface of the tape clean to cover his identity, the sticky side can’t be wiped without taking away the sticky. Balls of tape tossed aside by a suspect have been processed successfully for prints, but first the tape had to be released from itself.

 

Separating folded duct tape from itself

What to do? Drop lots of a 2% chloroform tape release agent on the area where the two pieces of tape meet. Two people need to work together on this – one person places the drops continuously while the other person pulls the tape apart. The ends of the tape should then be folded over (about ¼”) and the tape flattened for 24 hours before doing anything else to it.

 

Adhesive-side developer

 After 24 hours, adhesive-side developer should be applied to the sticky side of the duct tape, allowed to sit for a few minutes, then rinsed off. The prints are clearly visible, can be photographed, covered with clear tape to protect them, viewed under an Optical Comparator, entered into the system, and sent off to AFIS.

 

Duct tape prints

 

 

Dashboard prints:

Up until recently, we could not collect decent prints from the dashboard of a getaway car in a reasonable length of time. Most car and truck dashboards have a slightly bumpy surface, more or less because it’s a selling point to non-criminal types – supposedly the pebbled surfaces mean no more pesky fingerprints to clean off if you’re a mom transporting kids after school. Sheila says the juice spills just get buried in the grooves.

 

But, it’s a potential fingerprint heaven for the CSIs who need to process the abandoned bank heist car. Think about it. If you press your hand onto a dashboard, your skin (with all the loops and whorls and arches and oils) is also pressing into the crevices of the pebbled surface. The problem is that a straight gel lift or hinge lifter will not pick up the prints effectively or may only pick up the top of the print.

 

Dashboard surface

 

 But, the investigator sees the possible print and doesn’t want to lose the opportunity to catch the crook. The answer in the past was to dust the likely area with magnetic fingerprint powder, then apply a Blue Glue gel and wait for the gel to cure before lifting it off the dash – about five hours. FIVE hours? The crook is getting away! No time to wait!

 

These days, the preferred lifting product (after applying the magnetic powder to enhance the print) is a transparent liquid silicone (PVS200 – polyvinyl siloxane), applied with an extruder gun. It flows down into the crevices, dries in six minutes, and gets into every bit of the print. After the polyvinyl dries, it can be lifted, and then placed on a backing card to preserve the print. At that point, it can be placed under an Optical Comparator, photographed, and sent off to AFIS for an ID/comparison.

 

This epoxy is not good for every surface (it rips paper, etc) but is very good for pitted, bumpy surfaces like alligator skin and dashboards. Gotcha!

Dashboard Lift

 

 

Planning to become a crime scene investigator? Then remember to collect the balls of duct tape tossed on the floor or in the garbage cans at the crime scene. Almost definitely, a great source for prints. And don’t forget your extruder gun!

 

*Photos taken by Patti Phillips at the Sirchie Education and Training facility in Youngsville, NC.

 

For more information about Sirchie and its products for the law enforcement community, please visit www.Sirchie.com.

 

 

 

 

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