Author Archives: kristylahoda

Mar12

Q&A with the Forensic Laboratory Chief of the Ohio Division of State Fire Marshal (SFM)

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It is my pleasure to welcome, Chad Wissinger, the Forensic Laboratory Chief of the Ohio Division of State Fire Marshal to my blog. I have had the privilege of working for him for nearly two years now as a contract explosives analyst. This post provides a unique experience to learn about forensic science and crime labs straight from the top.

*****

Kristy: When you were a forensic science major in college, was your goal to be the Chief of a crime lab one day?

Chad: When I was an undergrad, I always thought one day I would become the director of a crime lab, I just didn’t WANT to be one then. I knew Directors didn’t get to work on much evidence or do all the exciting things that I thought examiners got to do. Plus they had to actually manage people, which I knew I was not prepared for.

*****

Kristy: What area of forensic science did you want to work in after obtaining your degree?

Chad: As an undergrad I knew exactly what discipline I wanted to work in (fire debris and explosives). Between readings and labs that we had as undergrads, I came to think some of the other disciplines where not very exciting. With fire debris and explosions things burn and blow up, which to me is a little more exiting.

*****

Kristy: Did you get a job as a forensic scientist right out of college?

Chad: No, unfortunately I wasn’t willing to move very far from where I grew up, so that definitely limited my potential employment opportunities. I worked as a temp in a quality assurance laboratory for a few months before I got hired as an explosive examiner in the lab. I was very fortunate to have made contacts through some of my undergraduate research that resulted in me getting my first forensic job.  Networking as a student is key…

*****

Kristy: When you worked as an explosives analyst, was the job what you expected it to be like? If so, what did you expect the job to be like coming out of college? If not, how was it different than what you were expecting?

Chad: Yes, working as an Explosive and Fire Debris examiner was just as exciting as I always thought it would be. It was especially nice that every day was something different. No explosive case was ever like any other.

*****

Kristy: Are forensic science jobs easy to get? Why or why not?

Chad: When I graduated it seemed like Forensic Jobs were easier to get, but that was because there were far less colleges offering Forensic Science programs and the CSI craze was just starting, so there were not as many students interested in the field. However, with the number of college programs and the dramatic increase in students becoming interested in the forensic sciences, it is very hard to get a job in the field for today’s graduating students. It’s very competitive.

*****

Kristy: What is your advice to someone who wants to work as a forensic scientist and is deciding what to do in school? Or where to even go to school? Are there websites that list the various schools and what type of forensic concentrations the schools have?

Chad: My advice would be to get a good analytical chemistry/forensic based undergraduate degree. Nowadays, a Master’s in a forensic science will greatly increase a student’s qualifications and put them in the upper echelon of qualified applicants. A website that lists all of the undergraduate and graduate programs in the US is the AAFS website (http://www.aafs.org/colleges-universities). This website lists all of the schools that are accredited by the Forensic Science Education Programs Accreditation Commission (FEPAC). Lab directors do look at the qualification of the schools when considering hiring students; a school that has been accredited by FEPAC will probably carry more weight than those that have not.

*****

Kristy: How big is your lab and what types of evidence do your employees analyze?

Chad: We analyze evidence from fires, explosions, hazardous incidents, and other criminal activity. This includes the forensic disciplines of fire debris, explosives, latent print processing, forensic video/audio, and general chemical and physical analyses.

*****

Kristy: Can you give a description of the different aspects of your job as a Chief? In other words what all does your job entail?

Chad: My job as the Chief of the lab is very broad in its responsibilities. Between preparing the lab for accreditation, managing the day to day operations, and speaking frequently to investigators and students in the forensic sciences, I stay pretty busy.

*****

Kristy: How is the State Fire Marshal’s laboratory set up? (i.e. who brings your evidence, etc.)

Chad: Evidence is submitted to the lab from Fire departments throughout the State of Ohio. In addition, our own SFM investigators account for just under 50% of our case load. We also see some submissions from police departments, Sheriff’s offices, and some federal agencies. Essentially any law enforcement agency or fire department can submit evidence to us. We do not accept evidence from private entities or citizens.

*****

Kristy: What is the hardest aspect of your job?

Chad: The hardest part of my job would have to be the paper work, there’s a lot to be done and it’s not always the most exciting part of my duties.

*****

Kristy: What is the most interesting aspect of your job?

Chad: Probably getting out and talking to/assisting fire investigators; be it at training seminars or at crime scenes. Most investigators are always willing to learn better ways to collect evidence or just to understand how we can help them in their investigations.

*****

Kristy: Since you are more on the administrative side of things now, do you ever miss working in the laboratory?

Chad: Yes, I do miss working on evidence from fires and explosions; however, I think I enjoy my job now more than I did as an examiner. I love getting out and talking about forensic science and what we do.

*****

Kristy: Is working in a crime lab anything like what it is portrayed to be like on TV?

Chad: Not exactly, we don’t carry guns, drive Hummers, and crimes aren’t solved in 45 minutes. However, some of the basic principles of the science and the way we test evidence that are presented on TV are true, they are just over dramatized.

*****

If you have any questions for Chad or I, please direct your question accordingly in the comment section. Also, I have to moderate all of the questions, so it could take a day for your question to be visible on the post.

Feb25

Free Forensic Book Giveaway!

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I’m hoping to do a book giveaway every two months on here. The first free book is titled: “The Forensic Casebook: The Science of Crime Scene Investigation” by N.E. Genge

Here are the rules:

1) “Like” my Professional FB page: Explosive Faith at: http://www.facebook.com/kristylahoda. I use it to notify people when I have a new post up. If you haven’t been following my blog until now, I write synopses of the latest in forensic news.

I also have a twitter account (@KristyLahoda) that I would love for you to follow, but it is not required for this contest.

2) In the comments section of this blog post, include what about forensics interests you. This can be anything! Let me know if there is something specific you would like for me to write about…in other words, what can I write that will cause you to want to read and comment on my blog?

3) When I have comments from 50 different people, I will wait three days to see if anyone else wants to play and then use a random number generator to draw the winning number. If I am given the number “38″, then whoever posted the 38th comment, will receive the book. You can just message me your address and I will mail it to you.

Be creative!

Feb23

Nubian Skeletons from the Middle Ages

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Kevin, one of my coworkers, told me he finds forensic archaeology interesting, so Kevin, this post is for you!

Can you imagine as a student, getting to analyze skeletons that are from 6 to 14 centuries-old? As an undergraduate??? For undergraduate and graduate students at Michigan State University, this must be a dream come true! The Department of Forensic Anthropology and Bioarchaeology has in its possession, on loan from the British Museum, 409 Nubian skeletons removed from Mis Island along the Nile in present-day Sudan. Their gravesites were dug up before the area was turned into a dam. In fact, four MSU graduate students worked on the excavation that took place in 2007. This along with the laboratory study of the skeletons is providing these students invaluable experience in their chosen field of study. I would not want to be competing against one of these students for a job, that’s for sure.

Now that these bones are at MSU, it is time for the students to make the “bones speak” in the laboratory. They are interested in learning about the Nubian diet, gender, health and disease, approximate age, and lifestyle to name a few. Little is known about this people group. The students have learned that these people suffered from many diseases such as scurvy, leprosy, and TB. Infant mortality was high. The bones tell of the hardships experienced and endured by the Nubians, such as the wearing of their teeth. The desert sand that mixed with the food they ate wore on the enamel. Many of the bones show signs of trauma–one skull had been cut open, perhaps by a sword. Before Mis Island became Muslim after 1400 A.D., it was Christian. They speculate that there may have been fighting during this time.

The data that they collect is put into a database that the British Museum runs. Perhaps once all of the data is collected, they will have a clear picture of the mysterious Nubians. There is a story here somewhere…maybe for one of my future novels.

Feb17

Federal Funds awarded to FIU professor to speed up Rape Case DNA Analysis

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My former graduate school advisor, Dr. Bruce McCord, who is now at Florida International University was awarded a $349,000 DOJ grant to perform research to speed up DNA analysis for rape cases. It currently takes at least 1 day to obtain DNA results for a rape case largely due to the fact that the rape kit sample obviously contains both semen AND vaginal fluids which must be purified and separated before the male DNA can be obtained. McCord believes that his proposed research can analyze the male DNA without separating it from the female DNA. The research project came about as a result of the backlog of rape cases in different counties in Florida. To perform the research the team needs to make simulations of the samples found in rape kits. These simulated rape kits may be hard to come by…but McCord is an expert in DNA analysis and he will find a way. Best of luck to you Bruce.

Nov14

Not All Explosives are Created Equal

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Here is my post that was on QueryTracker.net Blog.
QUESTION: I am writing a thriller and my antagonist is planning to make a pipe bomb.  Does it matter what type of explosives she uses?  For example, could something like TNT be used as an explosive in the pipe?
ANSWER: It does matter as not all explosives are created equal.  TNT is not an explosive typically used in a pipe bomb—it does not need to be contained to cause mass destruction.  Explosives are generally grouped into two categories: low explosives (LEs) and high explosives (HEs).  These are differentiated based on the speed of explosion.  LEs deflagrate, HEs detonate.
High Explosives (HEs)

Detonation occurs when the reaction front propagates (i.e the reaction proceeds) through the explosive at a speed greater than the speed of sound,  Detonation occurs at velocities above 3,300 ft/sec (2,250 mph).  For detonation to occur, the assistance of a primary explosive is required.  To provide sufficient energy for the high explosive to begin its energetic decomposition (i.e. the breakdown into chemical components as a result of the energy of the reaction), only small amounts of the primary explosive are needed because they are reactive to shock, friction, or heat.  Detonation results in a rapid release of energy and an accompanying shock wave.
Types of HEs

High explosives are categorized as primary or secondary based on ease of initiation.  When comparing the two, primary explosives are more sensitive to heat, friction, and shock and have less energy, and therefore less power, than secondary explosives.  Secondary explosives are less sensitive to heat, friction, and shock and are more powerful.  Primary explosives are used in detonators and initiation systems.  They can be used to ignite secondary explosives.  Secondary explosives are used in large quantities relative to the primary explosive and are typically used as the main charge.
Primary Explosives

Two common initiating explosives include lead azide and lead styphnate.  Lead azide is very sensitive to initiation by friction, heat, or shock.  The velocity of detonation for lead azide is around 17,500 feet per second.  That’s just over 11,900 miles per hour!  Lead styphnate is sensitive to static electricity and fire, but is less sensitive than lead azide to friction and shock.  Its velocity of detonation is similar to that of lead azide.
Secondary Explosives
Trinitrotoluene (TNT) is one of the most universally known HEs.  Cyclotrimethylene trinitramine (RDX) and pentaerythritol tetranitrate (PETN) are two favorites of terrorists.  In fact, PETN was the explosive that Richard Reid, aka The Shoe Bomber, had concealed in his shoe in an attempt to blow up American Airlines Flight 63.  Another example of a high explosive is ammonium nitrate-fuel oil (ANFO, used by Timothy McVeigh and Terry Nichols in the bombing of the Alfred P. Murrah federal building in Oklahoma City in 1995.
Low Explosives (LEs)

Low explosives are propellants that burn in open air, but deflagrate (burn rapidly) when initiated in confinement.  LEs might not sound that dangerous since they burn, but they can be extremely perilous when used improperly.  In fact, they can even “act” as high explosives upon deflagration given the proper conditions when initiated, such as containment.  Simply stated, deflagration = explosion when confined.  When the LE deflagrates, the burn is faster than in open air.  However, it does not burn as rapidly as detonation occurs.  The reaction front propagates through the low explosive at a velocity less than the speed of sound.  As a result, low explosive deflagration reactions occur at a lower reaction front pressure, velocity, and temperature than HEs.
Types of LEs

There has been a strong emphasis in counterterrorism literature on high explosives analysis, but the majority of incidents in the US have been due to LEs such as black powder, smokeless powder, improvised explosives, and fireworks. These are the types of explosives that are used in pipe bombs.
In summary, low explosives require containment to deflagrate.  High explosives require primary explosives to initiate detonation of secondary explosives, but are destructive without containment.  After an explosion, there are a number of law enforcement activities that are launched at the crime scene and crime lab including an investigation, a crime scene search, evidence collection, sample preparation, and forensic analysis on the decomposition products of the explosives—called post-blast residue analysis.  The wealth of forensic information obtained post-blast is amazing and should give pause to anyone considering bomb construction.
Oct25

Forensic Analysis of the 1993 World Trade Center Bombing

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The United States was forever changed by the events that took place in NYC on Friday, February 26th, 1993.  It was the first terrorist attack by Middle Eastern extremists on U.S. soil.  On the second floor of the parking garage underneath the World Trade Center tower 1, an explosion occurred that left a crater 150-feet wide by several stories deep AND high.  A forensic investigation was launched that involved chemical and physical analysis of the samples, analysis of the explosives scene, and forensic accounting.

Chemical Analysis

The FBI was one of the investigative agencies involved.  At the time of the explosion, Dr. Bruce McCord, my former graduate school adviser was an explosives researcher for the FBI in Quantico.  Some of the novel methods of explosives analysis developed by McCord and coworkers were used to help determine the chemicals found at the scene.  It was eventually determined that the explosive was over 1,000 lbs of urea nitrate.

The forensic investigators had a difficult time determining what explosive was used in the bombing.  As I mentioned above, it was determined to be a urea nitrate bomb, however, urea and nitrate individually were found all over the place in the parking garage after the explosion.  Urea’s presence was largely due to road salt and sewage.  It was wintertime and NYC used bio-friendly urea as ice melt.  There was also eighty pounds of sewage covering the area due to busted sewer mains.  Both of these factors contributed to the urea.  Nitrates were present in the parking garage due to the prevalence of acid rain as well as from automobile exhaust.  Individually, the presence of urea and nitrate was legitimate.  This made it next to impossible to determine that the explosive was urea nitrate.  As a result, the chemicals from the scene were inconclusive, but drums containing the chemicals used to make urea nitrate were discovered as you will soon read so it’s hard to believe it was anything but urea nitrate.

  • An aside: As a result of this issue, one of my major dissertation projects was an environmental survey performed in conjunction with the FBI to determine what types of ions are ubiquitous in the environment.  It is important for forensic investigators to know this in order to determine what is potentially present from a crime scene and what was already present in the surrounding environs.  I will discuss this more in my next post.

Crime Scene Analysis

The big break in the WTC bombing was from a vehicular fragment.  Forensic scientists were unable to collect explosives residue due to the sewage contamination, but a VIN—vehicle identification number was located and traced to a Ryder truck rental in Jersey City, NJ.  Now here is a piece of history that every law enforcement agency would wish for during an investigation.  Mohammed Salameh, who rented the truck, reported that it was stolen the day before the explosion and called wanting to get his $400 security deposit back.  Needless to say, authorities were ready and waiting for him when he went back to collect.

Forensic Accounting

Thanks to a search of Salameh’s possessions, investigators discovered Nidal Ayyad, a chemist working in NJ.  They were able to find traces of urea nitrate and other explosives at a safe house.  Further investigation led to a storage area rented by Salameh that housed urea as well as other chemicals commonly used for making explosives.  A letter was received in early March by the New York Times claiming responsibility for the bombing.  DNA from saliva on the envelope was matched to Ayyad.

Forensic Science is a Team Effort

This investigation is a good example showing that oftentimes it takes multiple forensic disciplines to solve a crime—especially a big case like this.  Cooperation not just across disciplines within an agency, but across agencies is a must in order to answer the important questions: Who did it?  How was it accomplished?, etc…

Sep27

Tracking Marijuana and Ivory Tusks by Their Genetics!

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Heather Miller Coyle, a forensic botanist at the University of New Haven, has worked for the last three years developing a genetic database of various types of marijuana plants.  Why is this important?  Ideally, it will help law enforcement trace a marijuana seizure all the way back to the geographic area of production.  The article doesn’t mention this, but I imagine that if there are multiple areas of a certain type of marijuana plant grown across the globe, it might provide a drug connection link.  How does the database work?  Ms. Coyle determines the genetic code of various strains of marijuana plants and inputs it into her database which provides a genetic fingerprint for the various plants.

The drug database reminds me of an article I read a few years ago on ivory poaching.  The genetic information garnered from confiscated elephant tusks is being compared to a database of genetic information collected from elephant dung from 28 areas across Africa.  The comparison is used to determine the locations of various poaching hot spots since they can determine pretty accurately where the elephants originated from the tusk DNA and compare it to the dung database.  This is only possible due to the genetic variations of different elephant groups across Africa.  Elephants from the west and central African forests and savannahs can be distinguished about 100% of the time from dung DNA while elephants from east and south Africa are distinguished about 80% of the time.  The genetic variation is higher among the different forest groups due to isolation (i.e. not as much breeding among elephant types).

I really know nothing about genetics, but find it truly fascinating!

Sep24

Aluminum Explosions – New Model for Twin Tower Collapse

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I didn’t realize that there were conspiracy theories floating around about what actually caused the World Trade Center twin towers to collapse…until I read about the new collapse model.  It makes sense—there are always conspiracy theories to any major world event, but I just assumed that the airplanes crashing into the buildings would have been proof enough of what caused the towers to fall.  Not so for conspiracy theorists…they say that the airplanes were just decoys for the supposed explosives already planted within the towers.

Conspiracy theorists have used observations from 9/11 to explain why the current explanation doesn’t jive with reality.  Some of these include the fact that there were explosions, that the explosions occurred on floors below the floor levels that were on fire, molten metal coming out of the windows, the time between the crash and collapse, and then the rapid collapse.  Christen Simensen of SINTEF has detailed his new collapse model in the journal, Aluminum International Today.  It should lay to rest all of the conspiracy theories because it provides an answer to the questions.  It’s really actually quite simple.  He says that there was a chemical reaction that produced an explosion between the molten aluminum of the airplane bodies with the buildings’ sprinkler systems.

He is suggesting that each plane tore into steel as it entered the buildings, gashing the fuel tanks setting the fuel on fire.  With nowhere for the heat to escape, within an hour, the area would have heated up to 660 °C (1,220 °F) which is the melting point of aluminum (Al).  The molten Al would have continued to heat up to a temperature between 800 and 850 °C (1,470 to 1,560 °F).  Molten Al flows like water and would be so hot it would drip through cracks and onto floors below.  As it’s dripping through ceilings and onto one floor after another it reacts chemically through a series of exothermic reactions with the water held in each floor’s sprinkler system.  An enormous amount of hydrogen is produced and the temperature at the reaction site raises to between 2,200 to 2,700 °F!  At this point, one floor will explode followed by another.  The top of the building will begin to fall on the lower part of the building causing the entire building to collapse within seconds.

And just in case you think that this chemistry is nebulous, since 1980 alone there have been over 250 accidental water-molten Al explosions worldwide.  Pittsburgh’s Alcoa, the world leader in Al production, has done a number of Al-H2O explosion studies.  They reacted 30 kg (that’s 66 lbs) of Al with only 20 L (5.3 gallons) of H2O.  The reaction caused a 30-meter diameter (98 feet) hole!  Each fuselage of the airplanes that crashed into the world trade center buildings housed 30 tons of Al.  That reacted with a lot more than 5.3 gallons of water and down goes two buildings putting an end to the planted explosives conspiracy theories.

Aug28

Explosives Detection at Airports

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As a result of the Pan Am Flight 803 over Lockerbie, Scotland in December of 1988 as well as airline bombings over Africa and Columbia the following year, the United States passed the Aviation Security Improvement Act of 1990 which started the U.S. on the track to finding an explosives detection technology to prevent similar disasters.

Shortly after the September 11, 2001 attacks, President Bush signed the Aviation and Transportation Security Act into law.  This placed the TSA under the U.S. Department of Transportation.  One hundred percent of all luggage was soon required to be screened for explosives.  There are multiple ways that luggage is screened for explosives in airports in the United States: Explosives Detection Systems (EDS) and Explosives Trace Detection (ETD) also called Traces Explosives Detection (TED).

EDS uses Computer-Aided Tomography technology, i.e. CAT scans.  They detected the density and mass of objects within luggage.  Explosives have a fairly unique range of densities.  X-rays produced from the CAT scans are translated into cross-sectional images by computer software whose densities are then compared to densities of known explosives by software algorithms.  The operator can inspect the item if something suspect is indicated.

ETD is  something more visual at the airport and is used in a few different ways (that I know of).  One way is to use an “electronic nose” which is sampling the ambient air for explosive vapors.  This technique requires high vapor pressure explosives such as organic peroxides mainly used in Improvised Explosive Devices (IEDs).  Another ETD is a portal.  When a person walks through this, air is blown over them and then sucked into the instrument and collected at a filter where the sample is preconcentrated.  The filter is heated and the vaporized particles are carried to the sensor where the Ion Mobility Spectrometer (IMS) is used to determine if the sample contains an explosive(s).  Remember an ion is a positively or negatively charged particle.  The ion particles can be identified as to whether or not they are from explosives based on the length of time it takes them to get to the detector.  A third way is when, the luggage screener pulls you from the conveyer belt because  something suspicious was seen in your belongings or maybe you were selected for a random sampling.  I have been screened this way more than several times.  You are directed to an area behind the screening conveyor belt.  A different screener swipes your personal belongings or the items inside and possibly your hands with a paper disk.  The swipe is placed into an IMS and within 10-15 seconds, the swipe has been analyzed.  If explosive particulates were present on the swipe, the detector will sound and the type of explosive present will be indicated.

Let’s take a closer look at how IMS works.  When the swipe is placed in the oven of the instrument, the sample is vaporized and some of the vapor is ionized usually by the radioactive source beta emitter, 63Ni.  Ions of the sample are carried through a drift tube by what is called the drift gas.  Different ions will have different drift mobilities and as a result will separate and arrive at the detector at different times.  Typically smaller ions have a higher mobility than larger ions.  The IMS can operate in two different modes: positive ion mode and negative ion mode.  For explosives detection, the IMS will operate mostly in the negative ion mode.  Explosives such as those with —nitro groups (—NO2), for example trinitrotoluene (TNT), are very electronegative.  This means that they attract electrons very easily.  As a result, when ionized these types of explosives will form negatively charged ions, called anions.  If the IMS is in the negative ion mode and TNT is detected on the swipe, an alarm will signal on the IMS and indicate that TNT has been detected.  Triacetone triperoxide, TATP, is a high explosive that is a favorite of terrorists because of how easily it can be made.  It forms a positive ion (cation) when an adduct is formed (when it combines) with ammonium (NH4+).  If TATP is present when the IMS is operated in the positive ion mode, then an alarm will sound to indicate that TATP was detected.  As stated above, it is amazing how little time this screening process takes!

Have you ever wondered how these instruments at the airports are tested?  The National Institute of Standards and Technology (NIST) develops Standard Reference Material (SRM) that scientists use for validation of instruments and procedures.  A new SRM was developed in the Spring of this year to meet the American Society for Testing and Materials (ASTM) requirements for acceptable minimum performance of the Trace Explosives Detectors (TEDs).  This SRM contains calibrated solutions of the explosives RDX (an ingredient in C-4), PETN, and TNT.  The test protocol involves adding one drop of RDX along with a solvent blank to the swipe.  After the solvent is allowed to evaporate, the swipe is tested and the alarm should indicate the presence of an explosive.  This is repeated with the other two calibrated explosives solutions mentioned.   These calibration solutions were developed to be close to the detection limit (DL) of the instruments.  If they were lower than the DL, then the instrument would not be able to determine that an explosive was present when these calibration solutions were used.  This new SRM will allow for the TEDs performance and reliability to be routinely tested.

Aug26

Date Rape Drug Detection

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Scientists in Israel at Tel Aviv University have developed a sensor that can detect two of the three most common date rape drugs: 1) GHB (gamma-hydroxybutyric acid) and 2) ketamine.  A benzodiazepine called flunitrazepam, aka Rohypnol (known as roofies), cannot as of yet be detected by this new sensor.

Production of GHB is relatively inexpensive.  GHB is colorless, tasteless, and odorless and readily dissolves in liquid.  A deadly dose is 2.5 grams.  Ketamine is commonly used by veterinaries and pediatrics as tranquilizers.  Rohypnol, part of the Valium family, is a prescription drug and can be really dangerous when taken with alcohol.

Drugging a drink will slightly change the optical properties of the drink.  An optical sensor will detect this change.  The chemists are still trying to determine exactly how they want the detector to function.  Being discreet is high on the list so that the sensor can be used by a woman at a bar to check her drink.