Tag Archive for: blood

From Hot Breath to Big Toes … More Cop Terminology

ASCLD – American Society of Crime Laboratory Directors.

AFIS – Automated Fingerprint Identification System. Palmprint storage and search capabilities are also in place.

ALPS – Automated Latent Print System.

ASCLD/LAB – American Society of Crime Laboratory Directors/Laboratory Accreditation Board.

Acid Fuchsin – Reddish protein stain used to enhance bloody friction ridge detail of fingerprints.

Acid Yellow 7 – Fluorescent dye stain used to help visualize latent prints left in blood on nonporous surfaces.

Acid Yellow-7, Arrowhead Forensics

Acidified Hydrogen Peroxide – Solution used to develop friction ridge detail on cartridge casings by etching the surface of the casing not covered with sebaceous material (oils and/or fats).

Adactylia – Congenital absence of fingers and/or toes.

Adermatoglyphia – Extremely rare congenital absence of fingerprints.

Alanine – The most common amino acid found in proteins. Alanine is often
used to test latent print chemicals for an amino acid reaction.

Aluminum Chloride – A metal salt used to treat ninhydrin developed latent prints.

Amicus Brief – Legal document filed by someone not associated with a case but possibly has knowledge of a subject matter that may be of interest to the courts.  The person submitting the brief is known as amici curiae.

Amicus Curiae – Latin for “friend of the court.”

Amido Black – Bluish-black stain used to enhance bloody fingerprint friction ridge detail.

Anhidrosis – Medical condition that reduces or prevents the body’s ability to sweat.

Benzidine – Once described as the best technique for developing bloody latent prints on nonporous items, Benzidine has been linked to cancers and is no longer used.

Bichromatic ™ – A multi-colored powder used to process an object for fingerprints.

Boiling – Method used to re-hydrate the friction skin/fingerprints/footprints of a deceased person. To process the prints water is boiled and them removed from the heat. The hand of the deceased is submerged in the water for approximately five seconds. The skin is then dried and the fingers and/or palm is printed.

CJIS – Criminal Justice Information Services Division.

Calcar Area – The area located at the heel of the foot.

Cheiloscopy – The study of lip prints.

Clandestine – In secret.

Cluster Prints – More than one fingerprint grouped/clumped/positioned in the same spot of a surface.

Comparator – A split image projection screen used to view and compare fingerprints.

Core – Center of a fingerprint pattern.

Dactylography – The study of fingerprints as a method of identification.

De-gloving – The accidental/unintentional separation of the skin from the hands or feet. This “skin slippage” often occurs after a body has been submerged in water for a period od time.

Diff-Lift™ – Fingerprint lifting tape made especially for use on textured objects.

Dorsal – The backside of the hand.

Erroneous Exclusion – Disregarding evidence without a sound basis for doing so.

Exemplar – The known prints of a known individual.

FLS – Forensic Light Source. Includes all light sources used in forensic examinations.

FRE – Federal Rules of Evidence.

Fingerprint Society – Yes, it’s a thing. The Fingerprint Society was conceived in 1974 by Martin J. Leadbetter.

Genipin – A reagent used to develop friction ridge detail on porous items. The result is a dark blue image that can be seen without enhanced lighting.

Hallux – A person’s big toe.

Sir William James Herschel – The first European to recognize and utilize the value of fingerprints for identification purposes.

Histology – The study of the microscopic structure of animal or
plant tissues.

Hot Breath Technique – Breathing on a latent fingerprint either to help visualize the print or to add moisture back into an older latent print. Also known as Huffing.

Hyperhidrosis – Medical condition that increases sweating. Sometimes caused by certain medications, or heredity.

Hypohidrosis – Medical condition that decreases sweating. Sometimes caused by certain medications, or heredity or damage to the skin.

IAFIS – Integrated Automated Fingerprint Identification System. The FBI’s first
fully automated AFIS computer database.

Image Reversal – Occurs when the friction ridges in a latent print are reversed. Unintentional transferred prints could occur when using rubber lifters. It’s even happened when items are stacked on top of one another (stacks of evidence bags, for example), causing a print to transfer from one item to the next. The same is true with books. A print from one page could transfer to the next page (after the book is closed for a long time). These prints are mirror images and should be obvious to a trained examiner.

Latent Print – Print that is visible to the naked eye.

Liqui-drox – Fluorescent (yellow) solution used to enhance/develop fingerprint friction ridge detail on the adhesive and non-adhesive sides of dark colored tape.

Loupe – Small magnifying glass used to examine prints.

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Evidence Collection: Paper, Plastic, or … ?

There’s more to evidence collection than merely bagging and tagging bloody clothing and spent bullet casings. Crime scene techs are highly trained, skilled members of police agencies and forensic laboratories who more often than not provide the keys to solving cases.

In the “good old days,” many officers, including patrol officers, collected their own evidence (some still do, especially in smaller departments). They plodded into and poked around crime scenes, determining what items they thought might be of some value and then tossed those things into some sort of container—a grocery bag, department envelope, cardboard box, and even the cellophane wrappings from cigarette packs. In those days there wasn’t a lot of consideration for sterility, and DNA hadn’t yet made its way on the “scene.”

When investigators finally discovered plastic sandwich and ziplock bags you’d have thought they’d won the lottery, because packaging evidence had suddenly become a breeze. The problem with those new-fangled containers, though, was that detectives were placing everything in them, not knowing they could be destroying or damaging evidence instead of preserving it. And that brings us to the question of …

Paper or Plastic?

There’s a simple rule of thumb for deciding which type of evidence packaging—wet evidence goes in paper containers (wet evidence can degrade if placed inside plastic containers) and dry evidence goes in plastic. Items that could be cross-contaminated must be packaged separately. There’s a rule of thumb for other types of evidence, too, and here’s a handy list for the proper packaging of those items.

Hair – Double packaging in paper is best. However, if the hair is completely dry, plastic will work in a pinch. Hairs recovered from different locations must be packaged separately and labeled accordingly. Tape all packaging seams.

Fibers – Dry, and tape-lifted, fibers may be placed inside plastic containers.

Rope, twine, and other cordage – Paper or plastic.

Paint chips – Place inside folded paper. Then place the paperfold inside an envelope.

Tools – Paper or cardboard.

Tape – Wear non-powdered gloves when handling tape. Submit samples inside plastic. If the tape is stuck to an item the item must be submitted with the tape still attached. Do not remove the tape!

Glass – Wrap in paper. Smaller pieces may be placed inside appropriate size cartons.

Arson and other fire evidence – Airtight metal containers. Unused paint cans work best.

Dried stains – Wrap stained item in paper or place inside cardboard box. Large items – moisten swab with distilled water, swab the stain, and package in paper or cardboard after drying.

Blood – Allow to air dry and then package in paper.

Evidence drying lockers

DNA – Do NOT use plastic!
And when I mentioned that wet evidence is packaged in paper containers I did NOT mean to pour liquids into paper bags. Instead, items that contain wet evidence (bloody and/or semen-stained clothing, etc.) should be placed into paper containers.
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Read Any Good Bloodstains Lately? The Endings are Killer!

Detective Sergeant Carl Catchemall studied the bloodstain pattern on and next to the ticking cow clock hanging on the kitchen wall. He stood there, staring, for what seemed like an eternity before turning toward his partner Hank Handsup. Then he tipped his bald, oval-shaped head back toward “the cow wall” where reddish splotches and dots of once-oozing blood contrasted sharply against the freshly painted, snow white surface. The cow’s tail moved from side to side with each tick and tock of the timepiece.

Tick Tock …

“I believe, Hank,” said the wise detective, “that our killer was right-handed, shorter than your own meager five-and-a-half feet, and was standing, not sitting, quite close to our victim, poor Mrs. Ima Ghostnow, when he pulled the trigger on what was most likely a revolver. That, my friend, is what I believe happened to our unfortunate victim.”

Tick Tock …

In the real world, to reach such a solid conclusion, it’s a must that detectives conduct a comprehensive bloodstain evidence investigation, using proper tools, techniques, supplies, equipment, and training. And, of course, experience always helps.

A good bloodstain training class typically uses actual blood, because nothing else accurately mimics the real stuff. Although, a decent substitute for the real deal is a mixture of Karo syrup and red food coloring.

During training classes students are exposed to nearly every type real-life scenario imaginable, but the first order of business is to learn the basics—characteristics of a blood drop.

Characteristics of a blood drop

– blood drops are formed by gravity

– blood drops cannot break apart unless contacted by an outside force

– larger drops travel further than smaller drops (due to mass, not size)

– blood drops always travel in an arcing path (impact injuries)

– size ranges from a few millimeters to few centimeters

– volume of a drop of blood is in direct proportion to whatever it’s dropping from (ax, stick, arm, leg, etc)

Crime scene investigators typically measure bloodstains that hit surfaces on the way up, not stains made by blood that’s on its way back down. Stains made when traveling upward are much more accurate for use as evidence because gravity is not as much of a factor in the pattern’s formation.

Types of Bloodstain Patterns

Impact – caused by high-velocity or medium-velocity wounds—gun shots or blows by an object such as a baseball bat or hammer.

Swipes (Wipes)– Caused by a bloody object being wiped across another surface. These stains are the reason for changing the name of the examination from “blood spatter” evidence to “bloodstain” evidence (not all patterns are caused by airborne drops of blood).

*Remember, terminology could and often does vary from one area to the next.

The Lingo

Cast-Off– Caused by slinging blood off objects in motion (a swing of a bloody hammer, or arm).

Drip and Flow– Caused when blood drops off one object onto another.

Projected– Caused by arterial spurts. Often seen in stabbings and cuttings.

The ability to effectively interpret bloodstain patterns is a science and an art. But, before investigators can dive into a crime scene, they must learn a bit of terminology, such as:

Angle of Impact– the angle formed between the direction of an individual drop of blood and the surface it strikes.

Back Spatter– blood that’s directed back towards the source of energy, such as a hand holding a firearm, or hammer.

Expirated blood – blood that’s forced from the mouth or nose where air (exhalation) is the propellant.

High Velocity Impact Spatter (HVIS)– bloodstain pattern caused by a high velocity impact, such as those caused by gunshots or fast moving equipment or machinery (saws, drills, etc.)

Point of Convergence – the point (two dimensional) where the direction of travel (blood droplets) intersect. Can be used to help determine where the victim was standing when the fatal injury was delivered.

Point of Origin –the point (three dimensional) where the direction of travel (blood droplets) intersect.

Stringing – a method used to determine the point of origin. Investigators tie strings at the blood drops, following the direction of travel. The point where the strings intersect is the point of origin. Lasers are sometimes used in lieu of strings.

Stringing You Along!

So what are the tools needed to conduct a proper investigation of bloodstain evidence? Well, for starters …

Luminol

Luminol is a chemical that exhibits a bluish-white glow (chemiluminescence) when mixed with an appropriate oxidizing agent. It reveals the presence of iron in hemoglobin, even in the slightest traces of blood found at crime scenes. In fact, Luminol is capable of detecting blood even if it’s been cleaned away, and in situations where the scene has been altered to the point where there’s no indication that a crime was committed. The older the stain the more intense the reaction will be. By the way, Luminol is not recommended for use on visible or wet blood, and the area must be photographed prior to it’s use because the glow tends to fade quickly.

Photo – Sirchie

When your fictional detectives find themselves searching a property with hopes of locating blood evidence, here are some places they should look: kitchen and bathroom sinks and their drains. The same for tubs and toilets. The cracks between moldings and walls and floors, and at the base of tubs and toilet tanks, drains, cracks and crevices of wood. In addition, tile floors, grout, carpeting (beneath carpeting, especially if the carpeting appears to have been freshly cleaned), dirty laundry, hampers, bedding, ceilings, lampshades, beneath table tops and chairs, mops and mop buckets, sponges, door handles and knobs, knife blocks and, well, the list is as broad as the imagination allows.

When using Luminol to detect the presence of blood, it’s best to turn off all lights before applying it to the suspected/targeted area.

Keep in mind that chlorine bleach flashes brightly when contacted by Luminol. This is a sign that someone may have attempted to clean the area. It’s also important to note that iron and copper particulates will react with Luminol, giving a false positive for a suspected presence of blood. As always with presumptive testings (drugs, etc.), a laboratory test is required for confirmation or exclusion.

Other false positives for Luminol include iron and copper particles. Luminol is a blood search tool, and suspected blood areas must be confir

Luminol has been found to deteriorate DNA evidence, therefore DNA evidence should, if possible, be collected and preserved prior to the use of Luminol or similar products, such as BLUESTAR.

Photo – Sirchie

BLUESTAR is also used to determine the presence or absence of blood. However, what sets BLUESTAR apart from Luminol and other blood reagents is that its use doesn’t require total darkness, nor does it deteriorate DNA. Another benefit to BLUSTAR use is that the color, intensity and duration differs from that of Luminol. Therefore, investigators are less likely to confuse blood and false positives.

 

Bloodstain Pattern Investigations at the Writers’ Police Academy and MurderCon

This fall at MurderCon, instructor David Alford is scheduled to present a fantastic and wonderfully detailed hands-on class about bloodstain pattern investigations, called The Art of Blood. Here’s a “first look” at the workshop.

“Violent crimes and accidents frequently involve the interpretation of blood evidence. This class offers the attendee the opportunity to learn how to determine the velocity and angle in which a bloodstain impacted a surface, and the 3-dimensional point of origin – where injury or bleeding event occurred . The instruction will include presumptive testing techniques of stains thought to be blood, as well as, searching crime scenes for latent blood with luminol when circumstances dictate that the area was cleaned by the perpetrator. Attendees will participate in hands-on activities to reinforce the learning objectives.”

About MurderCon/Sirchie instructor David Alford:

David Alford is a retired FBI Special Agent with 21 years of experience investigating violent crimes, terrorism and other cases. He was one of the founding members of the FBI Evidence Response Team(ERT)and conducted crimes scene searches on domestic and international violent crimes and bombings, including the Polly Klaas kidnaping and murder, the Unabomber’s cabin and the 9/11Pentagon scene.

He worked in the Denver and San Francisco field offices and completed his career at Quantico in the FBI Lab ERT Unit.During the 6 years in the FBI Lab, he was primarily responsible for overseeing and teaching basic and advanced crime scene courses throughout the US and many other countries. In the 6 years before the FBI, he was a Forensic Serologist, Hair and Fibers Examiner and Bloodstain Pattern Analyst for the Kentucky State Police Crime Lab.After retirement, David taught crime scene courses around the world on behalf of the FBI and US State Department.David has been with Sirchie as an instructor and sales representative for Sirchie’s RUVIS and ALS products for the last 10 years.David loves teaching and allowing students to learn through hands-on training.

Below, 2018 Writers’ Police Academy instructor RJ Beam details bloodstain patterns and why how they’re formed.

 

Speaking of MurderCon, there’s a murder to be solved there and it’ll be up to you to crack the case by using clues and evidence gained and gathered at the event. Oh, my, it’s going to be a “killer”!!

Details to be announced when the all new website goes live later this week. Registration is scheduled to open this month. Sign up date also to be announced later this week.

It’s exciting, and due to the new format space is extremely LIMITED. So be ready!!

Writers’ Police Academy presents MurderCon

 

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