evidence

KN, p. 261 “Forensics – What’s It All About?”

 

CSI Field Kit

Forensic: relating to or dealing with the application of scientific knowledge to legal problems (Merriam-Webster dictionary definition)

 

Back when I began in the Police Department (longer ago than I care to admit) the word ‘forensic’ was rarely used by police officers on the street. We knew to be careful if we were first to arrive at crime scene so that potential evidence wouldn’t be compromised, and the detectives pointed us to what needed to be preserved or uncovered so that a case could be proved. We dealt with physical collection, not analysis.

 

Analysis of the evidence is in the purview of the forensic scientists, the detectives, and the D.A.’s office.

 

Forensic Science is the broad term encompassing a wide range of forensic specialties and these days, is often shortened to ‘forensics,’ as in: ‘Let’s take a look at the forensics on the case.’ But what area of forensic science is required to solve a case? It depends. The prosecutor doesn’t need the findings from a dental x-ray when dealing with a known victim, but might need the results of a forensic toxicologist’s tests to determine a seemingly suspicious cause of death.

 

Most evidence is collected from the scene of the crime by trained local law enforcement personnel (that includes the photographer and the fingerprint person) in smaller jurisdictions, specifically assigned crime scene investigators (CSIs) in larger municipalities, and if needed, the forensic scientists themselves.

 

Underwater Recovery Bag

 

For the most part, the processing of body evidence is completed in labs or during autopsies in hospital, police, or State morgues. Other than body tissue or bodily fluids, things that shouldn’t be there (bullets, metal fragments, gravel, etc.) are sent out for testing. Experts might be tapped for their opinions about certain marks on the body that would have caused a blunt force trauma or other types of violent death, or for the condition of recovered remains.

 

Non-body evidence would be gathered from the scene and sent for processing to a lab that specializes in that area of analysis. Most States in the USA have centralized labs for various umbrellas of expertise, since smaller towns just don’t have the financial wherewithal (equipment and personnel) to handle finite investigations. In these days of post CSI TV shows, prosecutors and defense attorneys alike need to nail down the suspect’s guilt with absolute certainty for the public, so they rely on forensic test results and/or experts in the field to convince the jury of a suspect’s guilt or innocence.

 

So, who does what and how do they help the prosecution or defense teams? Listed below are some of the many forensic specialties.

 

Bloodstain Pattern Specialist determines the point of origin of an impact pattern as well as the movement of people after being hit or shot.

Drip Patterns

 

Digital Forensic Analyst recovers or investigates data from electronic or digital media, including audio and video recordings, and computers. These days, the skill set may also include the ability to investigate cellphones and other mobile devices for the call history, deleted messages, and corrupted SIM cards.

Forensic Accountant finds accounting discrepancies and interprets them for fraud or tax evasion cases as well as other criminal activities.

Forensic Anthropologist helps identify skeletonized human remains.

Forensic Ballistics expert investigates the use of firearms and ammo from a crime scene.

Forensic Botanist can determine where a body or suspect may have been because of the plant life found in or around the body or suspect.

Forensic Chemist detects and identifies illegal drugs seized during a drug bust, or found in a body.

Forensic DNA analyst does paternity/maternity testing or places a suspect at a crime scene.

Forensic Document Examiner interprets document evidence to determine authenticity of wills or potential forgeries.

 

Ninhydrin-Noveck sprayed on outer envelope

 

Forensic Entomologist exams insects in, on, and around human remains to help establish the time and place of death.

Forensic Facial Reconstructionist works with the skulls of recovered remains to identify them.

Forensic Geologist analyzes trace evidence establishing where a body was killed or whether it was moved to a different location.

Forensic Limnologist analyzes evidence collected in or around fresh water sources. Examination of biological organisms can connect suspects with victims.

Forensic Odonatologist compares dental records with teeth of the corpse when facial recognition isn’t likely or possible.

Forensic Pathologist applies principles of medicine and pathology to determine a cause of death or injury for legal purposes.

Forensic Photographer creates an accurate photographic record of a crime scene to aid investigations and court proceedings.

Forensic Serologist tests body fluids for rape cases or to determine if blood on the body belongs to that person or someone else.

 

 

Forensic Toxicologist analyzes the effect of drugs and poisons on the human body.

Trace Evidence Analyst analyzes trace evidence including glass, paint, fibers, hair, etc. that occurs when different objects contact one another.

 

Shoe companies, gun manufacturers, tire companies, etc. all keep records of their products made and distributed over time. In the age of computers, some enterprising criminalists created a variety of national databases with information on multiple companies and their products. The goal? To make it easier to match up shoe prints, or skid marks, or bullets to a particular person or crime scene. With a little luck, and research/chemical testing, even filed down serial numbers can be revealed, and a firearm can be traced back to its manufacturer, point of sale, and the owner. Tire impressions at a crime scene can be matched to a database to discover the make and model of a vehicle that may have been there. Distinctive shoe prints in the mud outside a house can be matched to a suspected burglar, or rule him/her out.

 

 

Who makes sense of all of the information observed and gathered at a crime scene? Generally, it’s a team effort, not the achievement of just one person that heroically solves the mystery of the who, what, when, where, and why of a crime scene. But the Forensic Scientists (or Criminalists) play a big role in identifying the pertinent pieces of the puzzle. They can answer questions about what they discovered while comparing body evidence, trace evidence, fingerprints, footwear impressions, drugs, ballistics, paper trails, etc., and the detectives or investigators most familiar with the case pull it all together.

Wet Lift Print as seen on a Comparator

Somebody asked me recently if just anyone can tack ‘Forensic’ in front of their job title. Not likely. For instance, a Forensic Accountant is much more than a savvy bookkeeper. They have advanced degrees and certifications specifically geared toward discovering whether a crime has occurred in complex situations, evaluating whether there might have been criminal intent, and then communicating that information in a way that a layperson can understand it. From Investopedia.com: “The reason we understand the nature of Bernie Madoff’s Ponzi scheme today is because forensic accountants dissected the scheme and made it understandable for the court case.”

 

This level of expertise is required in every area of forensic analysis.

 

Related articles:

Can’t Get Rid of the Blood?” 

Crime Scene at the Beach”    

“Who Murdered Jake?” in Kerrian’s Notebook, Vol. 2: Fun, Facts, and a Few Dead Bodies

                                      

*Photos by Patti Phillips

 

 

 

 

FW: “Where are the Evidence Collection kits made?”

NOTE: This was updated in August, 2019 to reflect new information.  🙂

Part 2 – information about Evidence Collection Training Classes held at SIRCHIE.

Click here for Part 1 – PW: “Have you been fingerprinted?”

 

 

During the first two days of Evidence Collection Training, we used a number of chemicals, fingerprint powders, and brushes, and employed several different fingerprint lifting techniques on a variety of tricky surfaces. We discussed the benefits of both cheap and costly Alternate Light Sources.

 

Our notebooks were filling up and theories of the perfect crime were flying around the class. We kept quizzing Robert Skiff, our instructor, (Sirchie Training Manager/Technical Training Specialist) about ways to ‘get away with the murder of the decade.’ But, as we learned, there is no perfect crime. That pesky trace evidence will always be waiting at every scene for the investigator to discover it, photograph it, tag it, bag it, and transport it without losing the integrity of the sample.

 

It was time to visit the plant – see how the powders, brushes, and other crime scene paraphernalia were made.

 

Sirchie manufactures most of its products in-house. The specialized vehicles for SWAT, bomb rescue, arson investigation, and surveillance work, etc., will now be built in North Carolina, along with the smaller products.

 

Security was carefully controlled throughout our tour. Most of our group writes crime fiction, so we are always looking for a way our fictional criminals can break in (or out of) a wild assortment of locations. As we walked through the stacks and aisles of products, we commented to each other on the smooth organization and many checks Sirchie had in place. Cameras everywhere. Limited access to the assembly floor. Labyrinths a person could easily get turned around in. If we got separated from the group while taking an extra photo or two, we were found and escorted back by an always friendly employee.

 

Of course, we couldn’t turn into rogue students anyway. Our fingerprints littered the classroom and they knew where we lived.

 

Security plays a part in the assembly model as well. Each product they create is put together from start to finish by hand. There are no assembly lines because of trade secrets and a dedication to preserving product integrity. Personnel are carefully screened before being hired and qualification for employment includes graduate degrees. No criminal history whatsoever is allowed. Every employee comes through the Evidence Collection Training Class so that they understand what Sirchie does as a whole.

 

Tool and Die Machines

 

 

Templates for the various products are created in-house. The operators of these machines are highly trained experts. Quality control is paramount, so training is constant.

 

 

 

 

                  

 

All the printing is done in-house. The printing area was stacked with cases of items being packaged for shipment. We saw strips large enough to process tire treads.

 

 

Field Kits are created for general use by investigators, but can be specifically designed for a special need. The small vials contain enough chemicals to test unknown stains and substances at the scene. Note the dense foam holding the vials and bottles firmly in place. The kits are usually kept in the trunk and probably get tossed around quite a bit. The foam insures against breakage during car chases and while bumping across uneven road surfaces.

 

There are fiberglass brushes, feather dusters for the very light powder, regular stiffer brushes, and magnetic powder brush applicators.

 

 

We were lucky enough to see fiberglass brushes being made.

 

 

If a handgun is seized for evidence, there needs to be a simple, yet effective way to track chain of possession.

*Bag the gun to preserve the fingerprints and

*drop the gun in the box.

*Then fill in the blanks on the box.

*Easy to stack and store until needed.

Think of all the cases that may be ongoing in a large jurisdiction – the evidence is not sitting at the police station. It’s in a warehouse someplace, and needs to be easily identified when required for court. In addition to several sized boxes for guns and knives, etc. Sirchie also provides an incredible assortment of resealable plastic bags for preserving evidence like clothing, unidentified fibers, etc.

 

 

Magnetic powder was being processed that day and then put into rows and rows of jars and jugs. Before it is sent out to the customers, each lot is tested for moisture content, appropriate ratio of ingredients and other trade secret tests. We joked about taking some back to class for the next round of fingerprint study and were surprised by how heavy the jugs were.

 

No, she’s not making bullets. She is assembling the cyanowand cartridges used for fuming with superglue.

 

SIRCHIE makes riot gear.

 

This is not a photo of something from a SyFy movie. At the center of the shot is a helmet template. The drills encircling the template are aimed at spots where holes are needed for each helmet, depending on the type of helmet in production. All the holes are drilled at the same time.

Helmet before anything has been added to it.
Helmet with padding.

 

 

 

 

 

 

 

 

 

Buckles for the helmets.
Padding is inserted after the buckles are attached.

 

 

 

 

 

 

 

 

 

 

Helmet component

 

 

Helmet component for neck

 

 

 

 

 

 

 

 

Helmet face guards.

 

 

 

Completed riot helmet.

 

 

 

 

 

 

 

 

 

 

The Optical Comparator, as well as the other machines, is built to order by hand.

 

While in the warehouse, we learned that if a product is discontinued, it is still supported by Sirchie. That means that if a law enforcement officer calls up with a problem a few years after purchasing a machine, he can still get help. Reassuring for jurisdictions with a tight budget that can’t afford to replace expensive equipment every year or two.

 

Sirchie sends supplies to TV shows, so next time you’re watching a fave detective or examiner lift prints with a hinge lifter, it may have come from Sirchie.

 

Thanks to Lee Lofland, host of Writers’ Police Academy, for the opportunity!

 

 

 

 

*Photos taken by Patti Phillips at the Sirchie Education and Training Center in Youngsville, North Carolina.

 

 

 

 

 

 

 

KN, p. 82 “Is that your footprint?”

 

 

 

 

It’s been raining off and on for days. It rained last week during a party, and people were tracking water and a little mud from the driveway runoff onto the porch all afternoon. We had so many different kinds of footprints that it would have made for a great crime scene demonstration.

 

Because, one of the most overlooked pieces of evidence at a crime scene is created by footwear.

 

Imagine: If a window breaks as a thief enters the premises during the commission of a burglary, the glass will fall into the house, and onto the floor or rug below the window. When the thief steps through the window, unless the thief has wings, he/she will probably plant a foot right in the middle of the glass. And walk through the house, most likely tracking minute pieces of that glass. That glass may also become embedded in the grooves of the sole of the shoe, creating a distinctive footprint.

 

If the investigating officer can place a suspect at the scene with the footprint, then there is probable cause to fingerprint that suspect and hopefully establish a link to the crime.

 

A new method of eliminating suspects right at the scene involves stepping into a tray that contains a pad soaked with harmless clear ink that doesn’t stain, then stepping onto a chemically treated impression card. No messy cleanup, immediate results, and it can even show details of wear and tear on the shoe. This can be a way to establish a known standard (we know where this impression came from) to compare with multiple tread prints at the scene.

Footwear Clear Ink Impression

 

 

Another tool for creating a known standard is the foam impression system. It takes a bit longer, (24 hours) but clear, crisp impressions can be made, including of the pebbles and bits stuck deep into the grooves and the writing on the arch. Very helpful when trying to place suspects at the scene. A rock stuck in the sole is a random characteristic that can’t be duplicated, so becomes another point of identification.

 

This is how it works: Somebody steps into a box of stiff-ish foam – a bit like stepping into wet sand.

 

An impression is made instantaneously. The detail is great – down to the wear on the heel.

Pre-mixed dental stone (made with distilled water and the powder) is used to fill the impression.

It takes 24 hours for the cast to become firm enough to pop out of the foam. We now have a permanent record of the footwear tread, which could be used for comparison to other prints found at the scene.

Footwear Casts

 

Occasionally footprints are found on the ground outside a window or in the gardens surrounding a house after a burglary or homicide. Ever see a crime show on TV where the fictional investigator makes a snap judgment about the height and weight of the owner of the footprint because of the depth of the impression? That’s merely a plot device and is not scientific evidence in real life. A crime scene photographer or investigator can photograph the footprint (next to a measurement scale), make a take away cast, and then compare the impression with those of the suspects or other bystanders at the scene. Beware: making a cast of the print destroys the print, so a photograph must be taken before pouring that first drop of dental stone.

 

Footprints can be found at bloody crime scenes as well. The suspect walks through the blood, tracks it through the house, cleans it up, but the prints are still there, even though not obvious to the naked eye. Blood just doesn’t go away, no matter how hard you try to get rid of it. It seeps into the cracks and crevices of a floor and even behind baseboards.

 

A savvy investigator will collect sections of carpet (or flooring) taken from where the suspect might have walked during the commission of the crime, then conduct a presumptive test for blood (LCV – Aqueous Leuco Crystal Violet), find a usable footprint, compare it to a known standard, and then be able to place the suspect at the scene.

 

 

 

 

Be careful where you walk. That footprint can be used as evidence.

 

 

 

*Photos taken by Patti Phillips

 

 

 

 

Scroll to Top