So What Did Margie Say about CSI...I mean Elementary

The 4/17/13 usual time slot for CSI: Crime Scene Investigation instead aired the repeat "Elementary" episode titled 'The Leviathan'.  Several times during the course of the show they stated 'if you eliminate the impossible what's left, no matter how improbable, is the truth'.

 

This mantra is exactly how many investigations are pursued only under the phrase 'scientific method' instead.

 

Basically, utilizing the scientific method, one reviews the facts and develops a theory or hypothesis.  Then (especially in a scientific field like bloodstain pattern analysis which tends to be more subjective than an instrumental analysis for drugs or DNA or explosives) the scientist endeavors to disprove their theory.

 

It is a process of elimination really.  Eliminating whatever isn't possible leaves only what is possible.  I can't tell you how many times in court while testifying that I have been asked if some other explanation is a possibility.  Having followed the scientific method and attempting to disprove the original theory, I was always able to testify that my experimentation established that several other suggested theories were not a possibility. 

 

Obviously, this is not 100% of the time.  Sometimes you may not be able to distinguish between patterns of expirated (blood being expelled from the body by force due to damage to or blood being present in the lungs or the airways) or impact (liquid blood being sent into flight by compression due to some forcible event) blood.  But then you rely on the other facts of the case.  Such as the injuries suffered by the victim.  That may also help to eliminate some possibilities and narrow down what is 'probable'

So What Did Margie Say About...Bones: The Party in the Pants

 

 

 

The 4/15/13 Bones episode titled "The Party in the Pants" used an abandoned building about to be demolished as the "dump site".  A dump site is as varied as the perpetrator.

 

Their usefulness is usually for one of two purposes: to destroy evidence and/or identity and hide the victim or to protect the victim so that the killer can visit, usually on the anniversary of the death.

 

A dump site may be out in the woods where the body is buried or covered with leaves and branches.  More respect usually requires that the victim is covered by rocks or stones.  There is more opportunity to recover evidence of the crime when the body is buried.  It is more protected from animal activity and environmental conditions.

 

The dump site may be a body of water.  The victims may be tied down with weights such as rocks or cement.  The body may be contained in a barrel or a 5 gallon drum or a suit case.  Usually, once decomposition occurs and gases are generated the body in a container will cause it to float.  If it's tied down and rotting occurs, then the weights are loosened and the body floats.

 

The simple dump is in the dumpster hoping that the body ends up in a landfill.  Once the body is dumped in tons of trash, it is difficult to find.  The usual indicators like smell or vegetation or overhead birds flying or bugs are commonplace in all the garbage.

 

Regardless of where the body is located, it is important to remember that it is really the remains of a victim and all attempts must be made to find the body or the evidence that remains.

 

Let's all remember those involved in the trauma and send good thoughts out to those in Boston.

So What Did Margie Say About...CSI: Backfire

 

The 4/10/13 CSI: Crime Scene Investigation episode titled "Backfire" showed an excellent forensic evidence collection and preservation technique and one procedure that was, in my opinion, far from excellent.

The wrapping of the beaten female victim in a tarp led to the collection of the tarp.  If you noticed, they put paper strips over the tarp to protect the evidence.  You should baffle an article like a tarp, a bed sheet, clothing articles, etc. so that no two areas of the evidence touches itself when folding it for packaging and/or transportation to the laboratory.  This procedure protects a transfer of biological fluids, trace, or other materials from one area of the evidence article from coming into contact with another section during the folding.  In doing it like this, any information obtained can be more substantial when running an investigation or testifying in court.

The second procedure that I would like to discuss is the stringing reconstruction of the bloodstain patterns.  The first thing that a bloodstain pattern analyst would do would create a 'wagon wheel' 2-dimensional reconstruction that would show the impact site.  From here, one would use the stains which were used to find the hub of the wagon wheel through their directionality to measure their length and width to determine a mathematical formula to determine the angle at which a particular stain struck the 2-dimensional surface.  From here the procedure allows the analyst to follow the angle and tie it off to a perpendicular structure which had been placed at the 2-dimensional hub of the wagon wheel.  What you have as a result is a 3-dimensional area in space where the blood source underwent the trauma which caused the impact spatter to fly in the air and strike the surfaces where they landed.  There was nothing close to this in the mass of wild strings that they had apparently arbitrarily placed at the crime scene.  The only thing close to realistic was the use of different color strings to distinguish individual patterns.

How disappointing that they wouldn't take the time to properly display the technique which could actually give them the information that they commented on in the show: the location of the victims when they underwent the beatings.

So What Did Margie Say About...Bones: The Partners In The Divorce

The 4/8/13 repeat episode of Bones titled "The Partners in the Divorce" begins with Hodges finding 'blue blow flies'. 

 

Entomology is a wonderful help to determine the PMI (post mortem interval) or the time since death.

 

There are tens of thousands of species of flies and it is important in Forensics what each one is attracted to.  Some like fruit, some like defecation, some like putrification, etc. 

 

The female blue blow fly smells the cadaverine, a gas released upon death, within minutes of its' release and can detect it within miles.

 

Flies don't have teeth so they use their tongues to suck the juices which is why they like the soft tissue areas or orifices like the mouth, nose, eyes, or wounds. 

 

Not only do they feast but this is a great place for them to lay hundreds of eggs.  The eggs hatch and become larva or what we normally call maggots.  The larva can grow many times their original size and at the same time reduce the body mass of the food source (aka: victim).

 

Once the larva grow several stages (instars) they crawl to a dark quiet place to become pupa.  They harden and look like brown or wild rice.  They can be within feet of the body and in the dirt or folds of clothing.  The next life cycle stage is that of the adult fly.

 

It is important for forensic entomologists to capture as many of the different stages of the fly that they can.  They watch their captures through their stages in conjunction with the temperature of the scene to determine 'degree days'.  This can give them a fairly accurate PMI.

 

Don't let it "bug" you, this is a great thing.  The different species can also determine the travel path of some vegetative drugs and whether or not a victim may have been moved from one location to another.

So What Did Margie Say About...CSI, Sheltered

The 4/3/13 episode of CSI: Crime Scene Investigation titled "Sheltered" begins with the idea of a potential animal bite in the victim's leg.  Even though this did not turn out to be the case, animal activity is often something that must be considered in crime scenes.  Someone who has died inside their residence, even of natural causes, and not found for a considerable time period may display damage due to pet activity feasting on the food source at the house.  

Oddly enough, it is thought that dogs hold out for a longer time period than do cats.  I have cats and sometimes their facial expressions seem to be saying "don't tempt us".  But that's another story.  

Meanwhile, outside animal activity may include the scattering of tissues and bones for several feet/yards away from the body.  Hair and clothing pieces from the body can be located in nearby nests of birds and/or rodents.  Shiny objects like buttons, jewelry, and cartridge casings are attractive to animals and may also be carried away to nesting places or dens.

 

The other interests in this episode revolve around chemistry.  The crane origami paper was treated with ninhydrin.  This reacts to the amino acids left within the remnants of the fingerprints within the porous paper and produces a purple coloring.  I would also like to note how proud I was to see Fin photograph each stage of the unfolding of the crane.  This procedure should be followed when anything needs to be unfolded, be it a towel, a bed sheet, or an origami crane.

 

Then they probably used luminol to locate the presence of blood.  Luminol reacts with blood and creates a chemiluminescent reaction.  Think of the glow of a firefly's butt.  In simple terms the same kind of reaction.  The thing about luminol is that it is usually used when only traces or non-visible blood needs to be located.  If you can visually see the blood stains there is really no need to utilize luminol.  

It should also be noted that the reaction is sensitive but not specific in reference to blood.  This means that it will react and "glow" with a reaction to a mere drop or two of blood in a bathtub full of water (sensitivity) but can react to things other than blood (specificity) like metals or vegetation.

 

The last chemical test that I'd like to talk about is that used for the detection for the presence of blood.  This is a screening tool and is only used as an 'indication' that blood is present.  Phenolphthalin is added to a swab which has been used to collect a test sample.  Hydrogen peroxide is then added to the swab and a pink color is considered a positive reaction.  If heme in blood is present, the O2 in the hydrogen peroxide will use is peroxidase-like activity to break down the H2O2 into H2O (water) and O2 (oxygen).  The O2 oxidizes the Phenolphthain to Phenolphthalein which is pink.

 

Now that you have had a dose of Chemistry 101, I must go.  My cats are giving me that eye look that says I should be giving them attention or they won't wait that extra day or two upon my demise...... 

So What Did Margie Say About...Bones, Maiden in the Mushrooms

The 4/1/13 episode of Bones titled "Maiden in the Mushrooms" reminds me that not all evidence is physical.  Sometimes you can get powerful information from the psychological evidence displayed at a scene.

 

Crime scene profilers will tell you that there are tells at a scene that will give you insight into the perpetrator's mindset.  For instance, a burglary where the lower level window screen is removed or cut into and the only room disturbed is that of a child and the only thing taken is change from a piggy bank, this is more than likely the work of a neighborhood kid.

 

This episode begins with a psychological profile of the victim buried face down.  This is similar I suppose to a victim whose face is covered with a towel or an article of clothing.  This particular action establishes remorse.  It doesn't mean that the killer wouldn't do the deed again if given the chance, only that they knew the victim or had some sort of bond with them and a small part of them senses regret or remorse.

 

A second concept was the clothes and shoes of the victim.  Obviously they belonged to someone who wanted to present as high class but the clothes were hand altered and the shoes didn't fit.  Therefore they did not belong to the rich and famous, only someone who wanted to appear so.

 

There is also an insight into the mind of someone who would not report taunting and stalking by someone they had a restraining order out on.

 

Sweets made the statement that the suspects action were impulsive obsessive, not calculated and meticulous.

 

Speaking of obsessive, there is the behavior of Bones in regards to the biting incident of Christine.  I'd say that it bordered somewhere on the verge of delusions of grandeur in that her daughter was perfect, or at least extremely above normal.

 

Personalities can leave tales at the scene and that's no April foolin'.

So What Did Margie Say About...CSI Fallen Angels

The repeat CSI: Crime Scene Investigation episode "Fallen Angels" airing on 3/27/13 was packed full of great forensic evidence.

 

It began with the shooting victim in the graveyard. Two cartridge casings that were located were considered not related due to their condition.  This occurs when a scene happens in an 'active' area where shootings or drug activities or excessive parties take place.  There is a tremendous amount of trash that must be "weeded out" from potential evidence that is relevant to the current event being investigated.  Usually the rule of thumb is to collect it even if there is a doubt but there are some scenes where it is sadly obvious that cartridge casings or syringes or used condoms have been there for quite some time.

 

They spoke of the lack of stippling in reference to the gunshot wound to the Reverend.  When a gun is fired the striking of the primer creates a small explosion which causes the gunpowder in the cartridge to ignite and send the bullet spiraling through the barrel of the weapon.  The unburned powder creates a pattern when it hits an object or a body.  When none is present this is an indication that the muzzle to target distance is such that the particulates fall away and don't hit the object or the body.  This gives a minimum distance that a weapon could be when fired.

 

The Medical Examiner utilized an Alternate Light Source to scan the body to search for potential evidence.  Some things absorb the light while others reflect certain wavelengths of light.  These reactions indicate a location to swab or collect potential evidence.

 

The fingerprint processing of the batteries in the flashlight is right on target.  Even when the item itself is wiped clean or contaminated with blood or dirt, there is a good chance that the protected batteries inside the item may provide at least a partial print.

 

There were several trace pieces of evidence but I will skip to my all time favorite form of evidence to help in an investigation: the BLOODSTAIN PATTERN!  The impact spatter on the top surface of the tennis shoes established that the wearer of the shoes was close to a blood source (the victim's head) when a forcible event (the shooting) occurred.  Blood spatter sizes are a clue to the force behind the forcible event.  The smaller the stains then the more force behind the event.

 

Great episode - worth the repeat.