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.
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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 Topic: DNA Analysis

I’m so pleased to have forensic expert Amryn Cross back with a question from a reader.

Welcome back, Amryn!


S.H. posed the following question about DNA analysis:
In my book, an investigator has a DNA test done on some samples and two profiles are found. The profiles are for half siblings, a man and a woman, who share the same father but different mothers.
What I need to know is this: Could they tell from just the brother and sister’s DNA that they are half siblings? I know they could probably tell that they’re related, but how clear would the match be? Would it be possible to say they share the same father? Or would they need to take a sample from dad to indicate that both were likely to be his children?
This is a great question about what can and can’t be gained from DNA testing. The tests performed in most crime labs will look at a set of 13 markers plus an additional marker to determine sex (amelogenin). For each of these 13 markers, a person will have two numbers. For instance, at marker number one, person A might have the numbers 10 and 13. We would say that their profile at that marker is a 10,13.
Using basic genetics, we know that a person inherits one of these numbers from the mother and one from the dad. In the above example, person A’s mother might have been 10,11 and the father might have been 11, 13. In that case, person A inherited the 10 from the mother and the 13 from the father. As you can imagine, this gets quite complicated when you have to look at several sets of these numbers which make up a DNA profile.
If you compared the profiles of a mother and her son or daughter, they would have at least one number in common at each of these 13 locations. If you also had the profile of the father, you could see that the child would also share at least one number with him as well. But for a brother and sister, things get more complicated. Look at this example:
Mother: 10, 11
Father: 13, 14
Son: 10, 13
Daughter: 11, 14
As you can see, each child received one number from their parents, but the brother and sister don’t share any numbers. Therefore, it is possible that we wouldn’t suspect they were related based on their DNA profiles. If you throw half-siblings in the mix, it becomes even less likely that the connection would be recognized if you didn’t have a reason to suspect it in the first place. It is possible that half-siblings would share no markers or at least not any more than unrelated people.
If you had the father’s DNA profile you would likely be able to say that he’s possibly the father of both, but not definitely. There are statistical calculations that can be done to help determine the degree of relatedness. Special testing of the Y chromosome would be able to tell that the father and son are definitively related but wouldn’t be helpful with the daughter.
As a side note, many crime labs won’t do paternity testing, and if your investigator didn’t already suspect these two people to be siblings, he would have a hard time getting a warrant for the father’s DNA profile. Of course, if the father willingly provided it, a comparison could potentially be made.
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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.
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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. 
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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.