Author Forensic Question: DNA and Donated Blood

Today, I’m posting a forensic medical question I had for Amryn Cross.

Jordyn Asks:

Can you tell if blood from a crime scene is from a donated pint of blood? If so, how?

Amryn Says:

You can actually tell the difference. A donated pint of blood will only have red blood cells and not the other components of blood (white blood cells, platelets, etc.). When the DNA from the donated blood is tested, the scientist would probably think it odd that they got little to no DNA yield (red blood cells don’t have nuclear DNA). They might chalk it up to degraded blood, or they might look at it under the microscope and find only RBC, which should make them suspicious. But probably the first indicator is that the blood at the crime scene would not clot if it were from a donated unit. The investigator may or may not pick up on that, but a crime scene tech probably would.

Jordyn Asks:

What about a pint of whole blood? Would it still be the same? Would small amounts of dry blood give DNA?

Amryn Says:

Whole blood would give DNA results but wouldn’t clot, so that would be something they would have to pick up on at the crime scene. If it was suspected and they wanted it verified, tests could be done for the preservatives in the bag.

Yes, if they were just droplets, they would still dry over time. And as long as it’s whole blood, it will give lots of DNA.

************************************************************************

Amryn Cross is a full-time forensic scientist and author of romantic suspense novels. Her first novel, Learning to Die, will be released in September. In her spare time, she enjoys college football, reading, watching movies, and researching her next novel. You can connect with Amryn via her websiteTwitter andFacebook.



Forensic Question: Solving Cold Cases


My question is about cold cases. Are you able to test for DNA from blood on a knife or clothes from 30-40 years old? Also, if the remains of a body were found in a mine shaft, could you tell the manner of death from that same time or even older, say, 150 years old? How would you do this and how long would it take? Thanks so much for your help!
Amryn Says:

Cold case investigations have come a long way with the use of DNA technology. Answers that would have been impossible 20 years ago are now commonplace. The problem with cold cases is often in the handling of the evidence. On the knife or clothes that you mentioned, when they were first collected from a crime scene 30-40 years ago, the investigator may not have worn gloves. That seems shocking given what we know now, but it wasn’t all that routine a few decades ago.

What that might mean for your DNA results is that you get a mixture—say, the victim’s blood and another unknown profile. Now, does that profile belong to the killer or just the detective or crime scene tech that handled the evidence without gloves? Without something to compare back to, you won’t be able to say.

Let’s assume best case scenario, though. If the bloody evidence was stored and handled properly, it is definitely possible to get a DNA profile from the blood present on a knife or on clothes. This can usually be done with routine DNA testing, which generally takes 2-3 weeks. Of course, for the purposes of fiction, the DNA could be “rushed” and then results would possibly be available as soon as 48 hours. This testing will probably be done at the police department’s or state’s crime lab.

As far as a body in a mine shaft, unless the body is frozen, it’s likely to be not much more than a skeleton by the time it’s found 30-40 years later, and certainly 150 years. However, if the manner of death was some sort of trauma (i.e. broken neck from a fall or stab wound where the knife grazes the bone), a lot can still be determined from bones.

In most cases, a forensic anthropologist would be the person to make that determination. Some states have one on staff while others call in an expert like Dr. Bass (founder of the Body Farm) when they are needed.  I would say the time frame for that sort of determination is at least a couple weeks, though I’m sure there are cases where it could be done faster. And I should also mention, many forensic anthropologists like to be present when the team is recovering the bones to make sure none are missed and to make observations based on the position of the bones.

**********************************************************************


Amryn Cross is a full-time forensic scientist and author of romantic suspense and mystery novels. Her first novel, Learning to Die, is available on Amazon. The first book in her latest series, loosely based on an updated Sherlock Holmes, is available for pre-order onAmazon. Look for Warzonein January 2015. You can connect with Amryn via her websiteTwitter and Facebook.

Forensic Question: Differentiating Twin Murder Suspects

Sarah asks:
If you have identical twins who are both suspects in a murder, how could you tell them apart?
Amryn says:

Identical twins are a hot topic in forensic DNA. Up until now, it’s been thought that identical twins have identical DNA and therefore are the perfect twist to a murder mystery. We’re finding out now that’s not necessarily true.

Strictly from a DNA perspective, research is showing that even twins have small minute differences in their DNA called SNPs (single nucleotide polymorphisms.) These aren’t routinely tested for in forensics because they’re pretty cutting edge, but such testing could be done (likely by a private lab) if the need arose.
Another option would be generating an antibody profile. When we’re born, we have an antibody profile like our mother. But beginning at birth and until the age of two, our antibody profile is evolving. It’s pretty much set in stone by the age of two and (as far as we know) doesn’t change throughout life. These antibodies are slightly different than the ones you make to fight off disease, but the important part is that they’re unique. Even identical twins will have different antibody profiles. This testing is new and is beginning to be used in conjunction with DNA testing.
Of course, this all depends on what type of evidence is found at a crime scene. Antibody profiling might be useful if some type of body fluid is found (i.e. blood, saliva, tears, sweat, etc.) but not so much with skin cells or hair. And, of course, even identical twins should have different fingerprints, so in a case such as this, DNA evidence might not be as strong as some other possible links.
If you’re interested in learning a bit more about antibody profiling, check out this article: http://www.americanlawyeracademy.com/antibody-profiling-forensic-evidence
************************************************************************
Amryn Cross is a full-time forensic scientist and author of romantic suspense novels. Her first novel, Learning to Die, will be released in September. In her spare time, she enjoys college football, reading, watching movies, and researching her next novel. You can connect with Amryn via her website, Twitter and Facebook.

Amryn Cross: How to Research Your CSI or Detective

Unless you’ve been living under a rock these past few years, you’ve probably seen an episode of the dozens of forensic type shows on television—all the varieties of CSI, NCIS, SVU, etc. They make the job look gritty and glamorous but hardly ever real. It makes for great entertainment, but not a lot of truth. This can be troublesome when you try to base your latest crime novel off something you’ve seen on television. 
Any writer writing outside their field of expertise knows some research is going to be involved, but in a field like forensics, it’s easy to be overwhelmed by the amount of information out there. I’ve compiled a short list of questions to get you on track when researching your CSI or detective character.

1.       Where does your story take place?

This is big one. If you’re going for authenticity, it’s better to narrow down your search to the area you’re looking at. For instance, New York City isn’t going to have the same structure to their police force or crime lab that a small town in the Midwest might have. If you’ve got a fictional setting, the good news is you can take bits and pieces from several places and make your own rules. Especially larger cities will have a website for the law enforcement agencies that might post job opportunities or a list of departments with descriptions. Utilize those.

2.       When does your story take place?

This may go without saying, but if your story is set in the 1980’s or 1990’s, having your detective catch the bad guy with DNA is not very believable. Technology and tests are always changing in forensics.

3.       What’s your character’s job title?

As cool as it looks on CSI, I can’t think of a place where the same person collects the evidence at a crime scene, determines the cause of death, runs the test on the evidence, interrogates the suspect, goes on stakeouts/undercover ops, and make the arrest. There are different jobs for each of these, and overlap will vary from place to place. In a small town, a detective might collect the evidence, interrogate the suspect, and make the arrest, but he or she won’t be determining the cause of death (that’s the medical examiner or coroner) or running the tests on the evidence (if it’s a small town, the evidence will probably be sent to the nearest crime lab.) At the same time, your CSI may collect evidence and nothing else if they work in a large city. Other places, the same people collect the evidence and test it.

4.       What agency does your character work for?

Research that specific agency and know what they specialize in. Most law enforcement agencies will work a variety of crimes, but many people are surprised to know that the FBI doesn’t typically get involved in murder cases or witness protection even though they’re often depicted doing just that. Find out how people within that agency are titled. Are they detectives, agents, inspectors, officers? Who carries a gun within that agency? You might be surprised. In some states, even the lab personnel are considered commissioned officers and carry a weapon.

5.       Don’t be afraid to ask questions.

There are lots of experts out there who are willing to answer questions about their experiences (myself included.) Most law enforcement agencies have a public relations person or department that can answer some questions for your specific region. One of my favorite online sources is the Crime Scene Writer’s group. This is a pool of people from all sections of law enforcement who are willing to answer writer’s questions. Make sure you search the messages first because there’s a lot to be gleaned from past questions.

Researching your law enforcement character doesn’t have to be scary. When in doubt, ask.
**************************************************************************
Amryn Cross is a full-time forensic scientist and author of romantic suspense novels. Her first novel, Learning to Die, will be released in September. In her spare time, she enjoys college football, reading, watching movies, and researching her next novel. You can connect with Amryn via her website, Twitter and Facebook.

Forensic Author Question: Fetal Bones


This month, Amryn has another great author question to answer.
Gloria F. asks: At what fetal age would bones show up with mom’s if mom was killed & stuffed in locker for 15 yrs? The body has been above ground in a disused bldg for that length of time.
Amryn says:
It’s important to understand that there are always exceptions to every case, so the answers I give are generalized unless otherwise stated. That being said, there are a couple factors at play here.
First of all, the process of skeletonization will vary with temperature and humidity. In this case, 15 years would be sufficient time for both the mother and the fetus to be skeletonized. This process can actually take as little as a few weeks in a hot humid environment. This is the sort of research done at the Body Farm (see my previous post for more info.)
A fetus will begin to develop its skeletal system around 12 weeks. From that point forward, the bones will grow harder and more dense. Theoretically, you could find fetal bones as early as approximately 15 weeks of gestation. The problem with this is, the bones are not fully articulated and would be very easy to scatter. Also, if you consider the average size of a fetus at 15 weeks, it only measures about 6 inches long. Those are some very tiny bones!
That’s not to say they couldn’t be detected by an anthropologist or medical examiner, but I would guess it’s more likely to find them if they suspect the woman may have been pregnant. Obviously the larger the bones, the easier they’ll be to see.
Another thing to consider is the idea of coffin birth or postmortem fetal extrusion. Basically, as the woman began to decompose, gases would build up in her body and could force the baby from her uterus… almost as if she was actively giving birth. This articleexplains it well. It’s something to consider as the fetal bones may not be found “inside” the woman when her remains are discovered.
*********************************************************************

Amryn Cross is a full-time forensic scientist and author of romantic suspense novels. Her first novel, Learning to Die, will be released in September. In her spare time, she enjoys college football, reading, watching movies, and researching her next novel. You can connect with Amryn via her website, Twitter and Facebook.

The Body Farm

Forensic specialist Amryn Cross is here for her monthly post on that elusive Body Farm.

Welcome back, Amryn!


Today I’m answering a question from an author who wished to remain anonymous.
I’d like to for my character to visit the Body Farm as part of their investigation. What is it really like?
First, let me preface this by saying that I haven’t actually been inside the Body Farm (technically known as The Forensic Anthropology Center at the University of Tennessee), but I can offer some insight on the facility. There are several good websites (http://fac.utk.edu/) and even a documentary out there, so I won’t try to cover the topic extensively. 
The Body Farm is a little over 1 acre situated behind the University of Tennessee Medical Center. The collection of skeletons (nearly 1000) is one of the largest in the world, and is housed under Neyland Stadium and in the Forensic Center below UT hospital. Once the bodies placed on the Body Farm are skeletonized and have reached the extent of their usefulness, many of them are transferred to the collection for further study.
When your character approaches the Body Farm, they’ll notice it’s located in the back of the UT hospital employee parking lot. It’s surrounded by wooden and chain length fences with barbed wire around the top. The area beyond this is hilly and covered with trees. 
Beyond this point, human bodies in various stages of decomposition are placed around the campus. Some exposed to the elements, others inside a car or concrete structure. Few are buried at various depths. All this is to allow the staff to study and measure the markers of decomposition. During the summer, the smell of death is ripe, even outside the fence. I had the dubious honor of parking in front of the Body Farm during my year of clinicals at UT hospital. Definitely an interesting experience.
The Body Farm is also used to educate law enforcement personnel as it is an integral part of the National Forensics Academy. The NFA hosts law enforcement agencies from all over the country to teach them proper techniques in forensic death investigation. This includes a crime scene with an actual body donated to the facility.
Though the facility at UT was the first of its kind, there are now four facilities in the US—University of Tennessee, Western Carolina University, Texas State University, and Sam Houston State University.
***********************************************************************
Amryn Cross is a full-time forensic scientist and author of romantic suspense novels. Her first novel, Learning to Die, will be released in September. In her spare time, she enjoys college football, reading, watching movies, and researching her next novel. You can connect with Amryn via her website, Twitter and Facebook.

 

How Much Evidence?

I’m so excited to host forensic specialist Amryn Cross as a new guest blogger to Redwood’s Medical Edge. To welcome her properly I asked my Facebook peeps what forensic questions they might have.

This was the first one:

How much forensic evidence does the court need to declare a missing person dead without a body?

Welcome, Amryn!!


Great question. The short answer is, it depends.
Any question involving the court itself has the potential to be highly variable. Different states have different laws, and some judges may allow things that others would not. That being said, I’ll answer this based on the most common occurrences in the U.S.
In most states, common law indicates a missing person may be declared dead after seven years with no evidence to indicate they may be alive. That means if a missing person’s bank account still gets regular deposits and withdrawals, if their name shows up on a deed in another state, or if they contact anyone this would be sufficient evidence that the person is alive (or their identity has been stolen, in which case this would be investigated).
If, after seven consecutive years of absence and a diligent but unsuccessful search for this person, there may be a court order issued to the registrar, instructing them to issue a death certificate.
As far as forensic evidence goes, a person may be declared dead sooner than seven years based on “sufficient evidence”. What constitutes sufficient evidence may be up to a judge in that jurisdiction.
One example includes finding a large pool of the victim’s blood provided it is a volume large enough that a person couldn’t have survived a loss that significant.
The other caveat is a person may be presumed dead because they were in imminent peril. This happens following plane crashes or mass disasters or even war. The passengers of the Titanic who did not arrive aboard the Carpathia in New York were declared dead in a matter of days and weeks. A similar thing happened after September 11.
Courts don’t automatically grant the order for a death certificate, even after the seven years. If a petition is made for a death certificate, the following criteria may be considered as reasons to deny the petition:
·         the absent person was a fugitive from justice
·         the absent person had a bad relationship
·         the absent person was having money troubles
·         the absent person had no family ties or connection to the community
Again, this is highly dependent on individual courts/judges. It always pays to check the laws in your particular jurisdiction.
Here’s a good article on the basics of declaring death and what happens when that person turns out to be very much alive. 
*********************************************************************

Amryn Cross is a full-time forensic scientist and author of romantic suspense novels. Her first novel, Learning to Die, will be released in September. In her spare time, she enjoys college football, reading, watching movies, and researching her next novel. You can connect with Amryn via her website, Twitter and Facebook.