[Morbid Legend] Human Pillars: Chinese Urban Legend

In 2006, a construction sites for relocating some water pipe lines in Hong Kong led to a discovery of 8 skeletons (1 adult and 7 children, according to all local news reports). The locals, especially those from one generation older immediately thought this was linked to this spooky old belief.

Continue reading

[新聞專題] 公主道掘地發現七童骸骨


新聞:公主道掘地發現七童骸骨 (蘋果日報) 及 何文田掘出8副陳年骸骨 (明報)




這邊的問題很多:(1)無超過十歲?(2)死了十年以上?(3)為甚麼疊在一起?但這次,我想先簡述第一個問題:如何決定小孩子骸骨沒有超過十歲。 Continue reading

“The Body in the Concrete”- Concrete Casket 101.

So last time, I expressed my concern on how the Hong Kong Police and Firemen had mistreated the crucial trace evidence, namely the concrete casket. And I also opposed their methodology. Some of the readers thought that police should be more experienced on handling these cases than me, and also thought that the law enforcement units had made this judgment after chains of thorough thinking.

I supposed I am not in a good position to comment further on how their approach was when they were at the scene. After all, I was not at the crime scene in person. Also, readers state that that was indeed the raw differences between theories, archaeology and the reality. I am only wishing to use the following space to replied to three of the main questions raised by the readers. I have also cited the Los Angeles Medical Examiners case report, in hope of the M.E. would be able to shed some lights on the questions the readers made from their study and research.

Question 1: The size of the concrete casket is too huge! May be they are not scanned because the law enforcement was not able to transfer them for scanning?

If you ever watched any crime shows on TV (of course, Bones is a good example. Everyone will yell “back to the lab!”), you will see they are always able to transfer whichever evidence they found back to the lab before further analyzing. Reality, not so much. This is how Ground Penetrating Radar comes into play. In archaeology, Ground Penetrating Radar (GPR) is used to detect and reflect any buried artifacts, monuments, archaeological sites. It is especially handy when archaeologists are about to look for hidden burial sites and buried remains. GPR allows noninvasive examination, and very helpful for experts and scientists to learn about the structure of the hidden architectures and bodies. Furthermore, size of a GPR is only about the size of a vacuum. Some companies even invented the GSSI Mini, which is about the size of a laptop for carrying scientists to have easy access in the field. All GPR and GSSI Mini come with a monitor, and very easy to connect to the laptop. That said, it is easy to document digitally the detected images. One may use slightly more time on using the GPR before stepping or unfold the crime scene, yet save the team and resources from doing extra and additional steps and procedures in the later investigation. In this case, that would be the suspicious broken palm, posture of the body, etc.

Question 2: It was mandatory to crack the concrete casket open, as the body was decomposing already.

News and police report claimed that the concrete casket was dried by the time of discovery. Yet, concrete would not dry but only cure and hardened. The hardening and curing of concrete, in other words, does not come from the evaporation of water from the chemical composition of the concrete. Rather the water molecules have transformed, merged and bonded together with the concrete particles as part of their chemical structure. An experiment pointed out that the mass of concrete before hardening/ curing is about the same with after [1]. The only slight difference between the mass was from the evaporation of the water on the concrete surface that with no cover. Last time, I have also mentioned that concrete is relatively porous. When cement hardens, it means that the water molecules and air molecules have filled in all those pores. This type filling makes concrete looks strong but indeed not. That said, it is relatively soft inside, while the outside of the concrete looks hard.

And for the body that was covered by the concrete, the decomposition of it liquefies from inside to outside, and all the decomposition was triggered by the enzymes in muscles. During the hardening process of the concrete, since it is a exothermic reaction (i.e. it releases heat in the whole process), the interior of the concrete casket would reach 175F in the first few days, which results an acceleration in the decomposition rate. After curing, the concrete becomes a good insulator that blocked the air and heat to reach the body, and thus successfully decrease the rate of decomposition again.

During the stage of decomposition, body liquids (any liquid in the body, you name it :)) would leak out of the body. Normally, as in general when a body is exposed to air, atmospheric air would help evaporate liquids and water. However, when a body like the one in this case is being buried in a concrete casket, all the fluid is trapped in the casket, and at the end turned the soft tissues into a mush. At the end, fluids would leak outside the casket, or concrete casket. This is not only something visual but also would give a strong odor. Evenly so, it does not mean an invasive act should be taken to the casket. Keep in mind that bodies starts breaking down the moment the heart stopped beating.

Question 3: Readers think that using merely textbook archaeology, i.e. using brush in the act, has not thoroughly considered the scenario at scene.

To be honest, this is some attitude that forensic scientists should have and maintain all along. In the forensic field, a lot of the tools we use are indeed very creative. For instance, you would find ladles on the autopsy table to scoop out fluid (for example inflammatory fluids in lungs) during autopsy; also would find those big stock pots in decomp bodies autopsy room for forensic anthropologists to do maceration. All these kitchenware is used with one and foremost premise: will not affect the quality of the collected evidences, or would not contemning evidences.

Los Angeles Medical Examiner Office claimed that there were only 5 cases of concrete casket located, till 2008, in the past 18 years in a report. They also stated in the report that, though cement and concrete affected the calculation or estimation of accurate postmortem interval, at the sam time they welly preserved all trace evidences [2]. In these 5 recorded cases, medical examiners were taken things slow, and excavate the bodies layer by layer in order to estimate the cause of death and time of death. Among all, LA medical examiners also indicated the frequent application of metal detectors and radiography in order to pinpoint the posture of bodes, and location. Sledgehammer and chisel are only implemented in a very much later stage, or only when they are sure it would not damage the body.

Back to the discussion, should we use heavy tools like sledgehammer and chisel, or only brush? Both. The foremost premise here is to not damaging the evidence. Only use heavy tools when the remains inside are well-documented. Also, the methodology with chisel should be go horizontally instead of vertically in order to reveal the context of the casket and the body.

Sad but true, concrete casket or related research is not commonly seen and discussed in the academia. These caskets can only open when all the conditions and situations are well-documented. In delicate crime scene like this one, officials should prioritize the preservation of crime scene in front of investigation just yet.



[1] Lesson 5: So, You Think Concrete Dries Out? (n.d.). Retrieved April 11, 2016, from

Toms, C., Rogers, C. B., & Sathyavagiswaran, L. (2008).
Investigation of Homicides Interred in Concrete—The Los Angeles
Experience. J Forensic Sci Journal of Forensic Sciences, 53(1), 203-207.

“The Body in the Concrete”- Dig or Not Dig, This Is the Question.

On March 30, 2016, Hong Kong local media, Apple Daily reported about a homicide that with a concrete-made casket. The concrete was found in one apartment in one of the neighborhood in Hong Kong, Tsuen Wan. The concrete casket was 1m x 1m x 0.5m and covered with a wooden box, and was placed in the center of the living room. Other than the concrete-wood casket, there were a lot of air-fresheners placed in the living room too. Police and firemen arrived the scene, and found the strong odor is originated from the wooden box in the living room. They decided to crack the casket, and handled the body to the M.E. right out of the casket. From the angle of forensic anthropology, and forensic archaeology, I would like to point out that the methodology police and firemen used to handle the casket is not appropriate.

Recap: Forensic anthropology is the combination of osteology and physical anthropology that applied in the legal context. Usually, forensic anthroplogists would only deal with human remains in advanced decomposition, skeletonization, human bone fragments, burnt remains, or other remains that have difficult time to give a positive identification from soft tissues.

Back to the case, first and foremost, the concrete casket. Concrete is the cured cement. Cement is a relatively alkaline material and very porous in itself. Concrete casket is very effective in insulating the body from contacting the air, which in turn, slows down the reproductive rate of bacteria within the body, as well as decreases the probability for flies laying eggs on the body. For, soft tissues decomposition mostly because the bacteria within digested our body and the occurrences of maggots. These two teeny tiny organisms enjoy the decomposition feast the most! Also, because the concrete could insulate the contact between the air and the body, the decomposition rate in general is slower in the concrete casket than exposing it in the air. That said, if the correct evidence collection methodologies used, a lot of physical, biological and trace evidences would be too preserved in the concrete casket. Therefore, without examine the concrete casket and use chisel or sledgehammer to break the concrete would be one serious wrong move, and here are the three main reasons:

1. Cracking the concrete casket is an invasive act. Once the concrete is cracked and broken, no one could recover it back to the original context. A fluoroscopic examination should be done and evaluated before any invasive act. With today’s technology, it would be easy and efficient to scan the whole concrete block before cracking it open. That way would allow the M.E. and corresponding law enforcement agents have a better understanding with the posture, number of bodies, and position of remains. Also, some of the remains might liquidfy or oxidize once contacted with air because of some chemicals they exposed to before concealed in the concrete. Straightly cracking it open, simply ignored this possibility.

2. Another risk of cracking open the concrete casket directly would be: what if there are more than one body? Although according to the intel and the missing person report, there was only one missing individual, and also because of this, police mainly focuses on looking for this particular person. Yet, if there are really more than one set of remains, directly using a chisel or sledgehammer without scanning the concrete in advance, would possibly damage the remains inside. The concrete casket, like the apartment, is a crime scene. One of the main missions for forensic anthropologist to determine first and foremost, would be the minimum number of individuals, or MNI. Anything in and out of the concrete casket is part of the evidences. Local news report stated that the right hand is cracked and broken because of the cement. Little did we know, if it was broken because of the cracking of casket, and thus resulted this postmortem trauma.

3. Direct usage of sledgehammer and chisel is not recommended. In forensic archaeology, the most useful tools would be those of carpenters–brushes, or even tooth brush. Only after fully documented the conditions of the casket would consider to crack the concrete. And would not use any chisel when getting close to the remains. That way, we could make sure the context of the body is well-preserved and complete-documented. Though this way is slow (could not deny this), yet can protect the remains and preserve the maximum amount of evidences, from pollen to hair to adipocere (aka grave wax).

Though body disposal in concrete is not a common case, it is definitely not the first. When handling body disposal like the abovementioned case, it is very important to keep in mind that speed of cracking the case is the least concern, as you have this fragile and one-time crime scene needed to handle and evaluate in optimum condition.

Forensics Daily #9: Dead Wives Tales

Q: are the dead wives tales true at all? Meaning, our nails and hair do grow after we died ?

A: Yes and No. Yes, because it does look like it grows, like illusion. No, because it is NOT REALLY GROWING.. Both hair and nails look like they grow after the heart stopped working because of the skin surrounding them are dehydrated. They shrink, and thus make it appear to be longer. Funeral homes sometimes will moisturize the bodies when they are doing the prep to counteract this.

Other than the hair and nails, the chin also dries out, and pulling towards the back of a skull, thus looks like more prominent. So does the goosebump effect, because of the contraction around the hair muscle (remember we talked about in the last few q&a, after we died, our muscles are not able to relax, not unable to contract!).

These all biological responses give the sense of horror!

Forensics Daily#7: Signs of Biological Death

Q: Seriously, in general, what will happen to our body once our heart stopped?

A: The story goes: when the heart stopped beating, no pressure to chase the blood around, gravity causes the red blood cells sink through and settle in the dependent parts. This results a red/ purplish discoloration, which we called LIVOR MORTIS Then we have RIGOR MORTIS, which is the stiffening in the muscles. It is because the brain stopped working, and stopped RELAXING (Not Contracting) the muscles. As well as, cooling of the tissues or ALGOR MORTIS. The latter two usually kicked in as soon as 20mins after death to 3 hours; capillaries will be congealed in 4-5 hours and maximum livor mortis occurs within 6-12 hours (though size of the patches increase within first 3-6 hours)

Forensics Daily #5: Hanging

*sorry that I had been away for a week as I flew all the way to Cyprus for a field school. Now everything is settled, and back with the daily Q&A 🙂

Q: what are the signs of a victim from hanging?
A: osteologically speaking, the hyoid bone is broken. However, if you are looking at a fresh body- with soft tissues, should find the following symptoms:-
1. Arms and legs are angled outward.
2. May find the neck has stretched few inches.
3. Face downcast.

Also, if you are looking for the validity of the MO, may also look for the stand or footstep for getting up to the thing they hung with. If that was absent, and the above symptoms are not found, together with the livor mortis(pooling of blood due to gravity kicked in not long after death), then it is possibly just staged and faked as hanging.

Forensics Daily #4- On suicide

Q:any relevance on using your favoured hand (i.e. Left- handed more likely on using left hand) on committing suicide? Also can manner of suicide tells you about the person?
A: No and yes. For the first half, there are studies showed that hand preference DOES NOT count as the factor of using which hand to pull the trigger. So do not simply judge the entry wound from the side of hand holding the gun. As for the second part, there are some we called more feminine way of dying and more masculine way. Usually feminine ways are taking pills, cutting wrist, while masculine contains putting the short gun into the mouth and blow the head off! Yet this remains controversial as it is 60% chosen by men and 30% chosen by women.

Note: this does not mean that simply by judging the manner of death/ suicide will be able to categorize the deceased. It just gives the investigators some ideas on the victimology, and the psychological condition of the dead.

**And of course, this is not to encourage you to suicide. I always say if you have the courage to die then you def have the courage to live on!

Tattoos: Forensic Considerations and Human Identification Pt.2

So we talked about how useful the inks are on getting a positive human identification (Click here to read about it before you continue with the following..)

This week we will go on and talk about inks from different period, or even removed would also help positive identification, which is particularly helpful in human identification in disasters. And for this part, the ink used for tattooing is the crux of the whole study.

Back in 19th Century, the ink manufactured for tattooing is obtained from burning a liter of oil soot. And 300g of the oil was combined with fresh urine (!). (If you are shocked, you are not alone). Though the manufacturing of the ink looks as raw and rough as it is, it has successfully been kept till today, and the collected specimen are now exhibiting in Romania. 

Tattoo ink penetrates as deep as dermis of human skin (though sometimes varies the thickness of the skin too). It is especially useful when the epidermis (outermost layer) of skin is destroyed in fire for instance. Tattoos are usually divided into two types, “amateur” and “professional.” It depends on depth the ink was injected. “Amateur” tattoo would have less densely packed pigment when compared with the professional ones. Before the application of medical lasers, surgical removal is the only option to remove tattoos. Since amateur tattoos have various depth of ink injection, it is more difficult to remove amateur tattoos than professional tattoos. Yet, it is the otherwise with the application of medical laser because of the density of ink.

Tattoo can also use to identify gang members, religious belief and some previous engagement or convictions. It is because tattoos can show the memberships of groups and gangs, when a person left the group, they may have the tattoo removed. Evenly so, removed tattoos could be traced with X-rays, infrared and lasers.

The theory behind using lasers to remove tattoo is to heat up the pigment particles, have them mover away from the dermal cells. “Pigments …migrates away from the tattoo site due to skin cells dividing or dying. Therefore, the depth of the ink in the dermis may also potentially be used to age a tattoo, another useful tool in human identification.” (Clarkson and Birch) That is to say, in any postmortem circumstances, movement of ink pigment could be observed in lymph nodes, which indicates the presence of tattoos even though it is invisible on the epidermis.

X-ray can also use to indicate not only the existence of tattoo, but also the time frame of the tattoos inked. How so?  “The older inks would be more visible than modern inks. This expectation is based on the known metal content in older tattoos ink.” (Clarkson and Birch) The metal component would reflect itself on the X-ray if detected.Yet, it was banned by the EU that the new types of ink should be metal free. Thus, by taking radiography images, it could possibly identify the time period, namely before or after the EU restriction for the individual to get the tattoos done.  

The alternative to “remove” the tattoo is by doing “cover-up” tattoo. With the help of infrared, it can show the proximity of color deposit onto the skin. Studies show that ink would deposit further into the dermis over time. This way, the latent tattoos are visible under a particular wavelength, and thus enhance the visualization for the forensic context.

See Part 1 Here.


Clarkson, Helen. and Wendy Birch. 2013. “Tattoos and Human Identification: Investigation into the Use of X-Ray and Infrared Radiation in the Visualization of Tattoos.” J Forensic Sci, September 2013, 58(5).

Miller, Daniel. 2014. “The human canvasses: Grisly exhibition of framed tattooed skin samples gathered by forensic scientist goes on display.” MailOnline.

Karsai, S., G. Krieger, and C Raulin. 2009. “Tattoo Removal by Non-Professionals–Medical and Forensic Considerations.” JEADV.

Tattoos: Forensic Considerations and Human Identification Pt.1

In 2005, the U.N. General Assembly designated January 27th as the International Day of Commemoration in memory of victims of the Holocaust. It is well-known that each survivor has one number on their forearm. These numbers are all tattooed by the time of their arrival at the concentration camp.

(Taken at Miami Holocaust Memorial in 2014. If you zoomed in, you will see a number tattooed on the arm, half covered by the statues of people)

According to the United States Holocaust Memorial Museum, it states that originally the numbers were not marked on the forearm but across the chest with indelible ink. Yet, the serial number would be removed by the time they died (from whatever reason), as the clothes would be removed. This made them have no way to identify the bodies. Then they developed a metal stamp that holds interchangeable numbers (made up with needles of course), and punch on the upper chest of the prisoner at one blow, followed by rubbing in the ink. They then further modified the equipment with a single-needle device, and changed the tattooed site to the forearm instead. Since then, the tattooing was performed at the registration till the camp was dismissed. 

Tattooing does not only for identification for living cases, like the one mentioned above in the Holocaust (though it is a tragic example to use). It is also very significant in forensic applications. The gigantic and disastrous tsunami in Thailand in 2004 killed thousands of people. Water and the heat worsen the decomposition of bodies; they were hardly to be recognized. Some of the bodies were identified, or provided clues for further identification leads by tattoos.

Tattoo patterns, and locations in fact tell a lot about the deceased (if it is in a forensic autopsy, or decomposed bodies), or the person. And, in the old days, social status. According to Byard (2013), Gang and prison tattoos are more often “crude” with antisocial message, an emphasis on death, and violence (what if someone is a bone lover like us, forensic anthropologists? Hmmm…). Whereas in western countries, choices of tattoos often only have decorative purposes, or personal meaning instead of a cultural meanings like those in gangs, or in tribal people. Western countries’ tattoos usually use customized tattoos to record relationships—“birth of children, or death of a friend or family member.” (Byard 2013) For the latter, they are called “commemorative tattoos,” it put cremated ashes from the person being memorialized mixed in with the pigment or the ink. Tattoos used to identify slaves and criminals like abovementioned case with Holocaust, can actually trace back to the Romans. Of course, some people would make good use of the ink, and tattooed their medical info or background on the arms, like blood type, certain genetic diseases.

Skins with tattooed pigment would decompose in a much slower rate than those without. Thus, it is possible to find a section of the tattooed skin in pretty good conditions even the body was found few years after, “even with quite pronounced putrefactive changes and loss of superficial skin layer,” according to Byard (2013).

Style and design of tattoos may give a pretty good background idea (age, or cultural background of the decedent). Sometimes, if it is a customized piece of art, it may allow the investigators to find the artist as well. The archaeological discovery of the Siberian princess, Princess Ukok in 1993 has well demonstrated the great preservation of tattoo.

Altai Aborigines says the mummy of princess Ukok is their progenitor. The tattoo on her arm in fact has hidden some important message for mankind. They believe that she passed away voluntarily to protect the Earth from evil spirits. The tattoo covers from her shoulder to her hand, and only left arm tattoo was preserved. Left should was the canvas for a mythical animal, an antlered deer with the beak of a vulture. “The antlers are adorned with vulture heads; a similar head can be seen on the back of the animal, the body of which is twisted, followed by a sheep with its head thrown back. The mouth of a spotted panther with a long tail is seen at the legs of the sheep.” The clash between vultures and hoofed animals symbolize the conflict between the two worlds: a predator from the lower world against the middle world (symbolizes by a herbivorous animal).

(Source: Siberian Times)

(Source: Siberian Times)

Though researchers found later that the Siberian mummy was in fact died from breast cancer and self-meditated with cannabis, which crumbled the voluntary death speech from the aborigines, it supports the studies Byard quoted, saying tattoos in ancient times signifies the special social status of that tattooed person. And for Princess Ukok, she might not be a real princess, but was believed as a shaman because of the visions she saw after using cannabis.

** Recently, the face of Princess Ukok has been reconstructed. Thanks to the well developed facial reconstruction techniques. Click here to have a look of how she looked like.**


Byard, W. Roger. 2013. “Tattoos: forensic considerations.” Forensic Sci Med Pathol (2013) 9:534-542.

Pravda.ru. 2011. “Tattoos of Princess of Altai conceal mankind’s biggest mysteries”

Siberian Times. 2012. “Siberian Princess Reveals Her 2500 Years Old Tattoos.”

United States Holocaust Memorial Museum. n.d. “ Tattoos and Numbers: The System of Identifying Prisoners at Auschwitz.” Holocaust Encyclopedia.