The Chris Watts Case: Opinion on the Toxicology

Thomas Mollett – June 2018

Following is my pro bono Opinion requested by and for true-crime author Nick van der Leek, who has written and published various eBooks on the case. This Opinion was provided in 2018.

Problem Statement: The decedent had a Blood Alcohol Concentration (BAC) of 0.128 g / 100 mℓ at the time of sampling (i.e. at autopsy). Does this BAC infer actual ingestion or is it possibly the result of postmortem synthesis?

Case History

Wikipedia Background

On 13 August 2018 at approximately 13:40, Nicole Utoft reported her friend Shanann Watts missing. Nicole stated that she dropped Shanann off at her residence at around 01:48 (the morning of 13 Aug) after Shanann returned from a business trip to Arizona. Nicole stated that Shanann was fifteen weeks pregnant at the time and was not feeling well during the trip.

Later that morning, Nicole became concerned because Shanann was not answering her cellphone calls or text messages and because Shanann also missed her doctor’s appointment that was scheduled for 10 am. Nicole went to Shanann’s residence and discovered her car in the garage. Nicole attempted to open the front door but a latch prevented it from opening.

Nicole called Shanann’s husband Christopher Watts, and requested him to come to check on Shanann as she believed Shanann may be suffering or was passed out due to some medical condition.

Officer Coonrod, who was called by Nicole, checked all the windows and doors and rear slider door and discovered all to be locked and that there was no way into the house. Officer Coonrod contacted Chris, who said that he was not working and that he was only five minutes away and on his way. When Chris arrived, Officer Coonrod entered the home in an attempt to locate Shanann and their two children but discovered that they were not there.

When questioned by Officer Coonrod, Chris said that Shanann arrived home from her business trip at around 02:00 am (the morning of 13 Aug). Chris stated that he woke up at around 5 am and began talking to Shanann about martial separation and that he wanted to initiate a separation. According to Chris, this was a civil conversation, and that while it was an emotional conversation, they did not argue.

Chris stated that he left the house that morning at about 05:30 and that Shanann was in bed at the time. A neighbour’s video surveillance system recorded this event. Chris stated that Shanann told him that she would be going to a friend’s house later that day with their two children but did not know the name of the friend. Chris stated that he went to a job site near Hudson to check in.

At Officer Coonrod’s request, Detective Baumhover responded to the scene and arrived at the scene at approximately 14:30 (13 Aug). Upon arrival, Detective Baumhover was briefed by Officer Coonrod and learned that Shanann’s personal effects, such as her cellphone, purse, wallet, and medication were located in the house. Upon entering the house, Detective Baumhover observed Shanann’s purse on a kitchen counter and a suitcase located at the bottom of the stairs leading up to the bedroom. A pair of women’s shoes were located close to the front door. Upstairs, Detective Baumhover observed that the bed in the master’s bedroom was stripped of its bedding, which was lying on the floor. Both Officer Coonrod and Detective Baumhover checked the bedding for foul play but found nothing to suggest as much. In a loft area, they located Shanann’s cellphone between two cushions of a sofa in the loft area.

On Detective Baumhover’s request, Chris walked them through the timeline again. He now stated that while Shannan arrived at around 2 am, they had the emotional conversation at about 4 am.

The neighbour’s video footage shows Nicole’s vehicle departing from the Watts residence at 01:48 am (Nicole dropped Shanann off at the house after fetching her from the airport). The video footage also shows Chris’s truck backing into the driveway at around 05:27, leaving a few minutes later.

The next day, 14 August, at approximately 07:00, Detective Baumhover learned that Shanann and the children had not returned to the residence. Detective Baumhover requested an immediate press release to be issued and initiated assistance from CBI and ultimately the FBI.

A two-day investigation revealed that Chris was actively involved in an affair with a co-worker, which he denied in the previous interviews.

Chris confessed that after he told Shanann that he wanted a separation, he walked downstairs for a moment, and when he returned, he saw their one child sprawled out on her bed, blue in the face, and that Shanann was actively strangling their other child. Chris said he went into a rage and ultimately strangled Shanann to death. He then loaded all three bodies on the back of his work truck and took them to an oil work site where he buried Shanann near two oil tanks and dumped the girls inside the tanks.

Chris was presented with an aerial photograph of the tank battery area and identified three separate locations in which he placed the bodies.

Drone searches were executed over the area. At approximately 16:15 on 14 August, investigators spotted a bedsheet in the field near the tank battery. The sheet matched the pattern of several pillowcases and a top sheet recovered from a kitchen trash can from the Watts residence earlier that day. The drone search also revealed the fresh movement of dirt, consistent with a clandestine grave, near the oil tanks.

Information from the aggregate Autopsy Report

Date and Time of Death: 00:05 – 16 August 2018 (pronounced dead)

Date and Time of Autopsy: 10:30 – 17 August 2018

Age: 34


I — History of being reported missing and subsequently being found unresponsive in an obvious state of death in a shallow grave

I-A — Asphyxiation due to manual strangulation

I-A-1 — Bruising of the anterior strap muscles of the neck (right and left)

I-B — Mild to moderate decomposition consisting of generalized discoloration, bloating, and skin slippage

II — History of intrauterine pregnancy, second trimester

II-A — Largely decomposed fetus and placental unit

II-A-1 — Found expelled from the gravid uterus

III — Toxicology

III-A — Postmortem – basic, Spleen blood:

III-A-1 — Ethanol – 128 mg / dℓ

III-A-2 — Blood Alcohol Concentration (BAC) – 0.128 g / 100 mℓ

Additional Observations

The stomach was empty

Cause and Manner of Death Opinion of the Forensic Pathologist, Dr. M.A. Burson:

Based on the history provided and the autopsy findings, the cause of death is asphyxiation due to manual strangulation by another individual. The manner of death is homicide.

Timeline of Events (based on provided version)

12/0817:00 17:30Dinner with Nicole, Addy, and CindyHad chicken salad and water
12/0820:00Original time of flight 
12/0823:00On flight 
12/0800:00On flight 
13/0801:00On flight 
13/0802:00Arrived home after being dropped by Nicole 
13/0804:00Argument with husband 
13/0805:00 05:30Argument with husband
Allegedly strangled children
Chris left the house with the bodies
13/0806:00 1 (Hrs after deaths)
13/0807:00 2
13/0808:00 3
13/0809:00 4
13/0811:00 5
13/0812:00 6
13/0813:00 13:40Nicole reported Shanann missing
Officer Coonrod arrived
13/0814:00 14:35Detective Baumhover arrived at the scene8
13/0815:00 9
13/0816:00 10
13/0817:00 11
13/0818:00 12
13/0819:00 13
13/0820:00 14
13/0821:00 15
13/0822:00 16
13/0823:00 17
14/0800:00 18
14/0801:00 19
14/0802:00 20
14/0803:00 21
14/0804:00 22
14/0805:00 23
14/0806:00 24
14/0807:00No sign of Shannan and children
Baumhover initiated searches
14/0808:00 26
14/0809:00 27
14/0810:00 28
14/0811:00 29
14/0812:00 30
14/0813:00 31
14/0814:00 32
14/0815:00 33
14/0816:00 16:15Drone searches
Grave spotted
14/0817:00 35
14/0818:00 36
14/0819:00 37
14/0820:00 38
14/0821:00 39
14/0822:00 40
14/0823:00 41
15/0800:00 42
15/0801:00 43
15/0802:00 44
15/0803:00 45
15/0804:00 46
15/0805:00 47
15/0806:00 48
15/0807:00 49
15/0808:00 50
15/0809:00 51
15/0810:00 52
15/0811:00 53
15/0812:00 54
15/0813:00 55
15/0814:00 56
15/0815:00 57
15/0816:00 58
15/0817:00 59
15/0818:00 60
15/0819:00 61
15/0820:00 62
15/0821:00 63
15/0822:00 64
15/0823:00 65
16/0800:00 00:05Pronounced dead (body found)67+Hrs
16/0801:00 681
16/0802:00 692
16/0803:00 703
16/0804:00 714
16/0805:00 725
16/0806:00 736
16/0807:00 747
16/0808:00 758
16/0809:00 769
16/0810:00 7710
16/0811:00 7811
16/0812:00 7912
16/0813:00 8013
16/0814:00 8114
16/0815:00 8215
16/0816;00 8316
16/0817:00 8417
16/0818:00 8518
16/0819:00 8619
16/0820:00 8720
16/0821:00 8821
16/0822:00 8922
16/0823:00 9023
17/0800:00 9124
17/0801:00 9225
17/0802:00 9326
17/0803:00 9427
17/0804:00 9528
17/0805:00 9629
17/0806;00 9730
17/0807:00 9831
17/0808:00 9932
17/0809:00 10033
17/0810:00 10:30Autopsy / Sampling10134
Table 1 – Timeline of key events


Time of Shannan’s death (strangulation) = Between 02:00 and 5:00 – 13 August 2018

The neigbour’s video surveillance system is important in this regard. This showed Chris’s truck pull into the driveway at 05:27 and leaving shortly thereafter. As far as is known, the video footage did not show his truck after 05:27 and before he arrived back at the house at 13:40–14:00 on 13 August. It can therefore be assumed that the Time of Death (TOD) was between 02:00 and 05:27 the morning of 13 August 2018.

For the purpose of this report the TOD will be assumed as ±05:00.

Objective Facts

Time of recovery of body (pronouncement of death) = 00:05 – 16 August 2018

Time of recovery of body after TOD = 67 hours.

Time of autopsy = 10:30 – 17 August 2018

Time of autopsy after TOD = 101 hours

Time of autopsy after recovery of body = 34 hours

Postmortem BAC Scenarios

Scenario 1

Assuming Shannan arrived intoxicated at the house at 02:00 and had nothing further to drink after arrival and between arrival and TOD at 05:00. Assuming thus that the BAC of 0.128 g / 100 mℓ reflects the BAC at the time of death: What was her BAC at the time of arrival to have had a BAC of 0.128 g / 100 ml at the time of death?


— Shannon consumed wine (based on history provided) [1 unit = 1 glass wine (125 mℓ)]

— Elimination rate of 0.015 g / 100 mℓ / hour (average for women)

What she consumed and absorption is not relevant here as the alcohol is already in the system and we are assuming a known BAC. The amount of food (or any other liquid) she may have consumed during this time is also not relevant as this will not influence the elimination rate.

02:00 0.173
02:00 – 03:000.173 minus 0.015^^^
03:00 0.158
03:00 – 04:000.158 minus 0.015^^^
04:00 0.143
04:00 – 05:000.143 minus 0.015^^^
05:00 0.128
Table 2 – Backward estimation of the BAC – from an end and known BAC of 0.128 g / 100 mℓ at time of sampling

Working back based on an elimination rate of 0.015 g / 100 mℓ hour, Shanann needed to have had a BAC of approximately 0.173 g / 100 mℓ at the time of arrival at the house to have had a BAC of 0.128 g / 100 mℓ at 05:00. This is assuming she stopped consuming alcohol at 02:00.

Table 3 – BAC vs Subjective Effects (Source)

As can be seen from Table 3, if Shannan had a BAC of 0.173 g / 100 mℓ (17.3%) when she arrived home, she would have been visibly intoxicated and subjective effects would have been clear.

Scenario 2

Shannan arrived with a BAC of 0 g / 100 mℓ at the house at 02:00 and then started to consume alcohol. How much did she need to consume between 02:00 and 05:00 to have a BAC of 0.128 g / 100 mℓ at the time of her death at 05:00?


— Elimination of 1 unit per hour (0.015 g / 100 mℓ / hour) after the first hour and the same during every hour after the first hour. She arrives at the house with a BAC of 0 g / 100 mℓ.

Consumption of Units per Hour (1 Unit = 125 mℓ Glass of Wine = 0.02 g / 100 mℓ)

TimeIntake & EliminationBAC FluctuationBAC
02:00Completely Sober 0.00
02:00 – 03:00Plus 2 Units Intake+0.04 V
03:00  0.04
03:00 – 04:00Plus 3 Units Intake+0.06 
 Minus 1 Unit Elimination-0.015 V
04:00  0.085
04:00 – 05:00Plus 3 Units Intake+0.06 
 Minus 1 Unit Elimination-0.015 V
05:00 (TOD)  0.130
Table 4 – BAC increase from 02:00 to 05:00 if consumption started at 02;00 from a BAC of Zero

With reference to Table 4, this means that Shanann had to consume approximately 8 glasses of wine in 3 hours to have ended up with a BAC of 0.128 g / 100 mℓ at the time of her death.

Opinion & Conclusion

To interpret postmortem toxicology results is a complicated process and should be done with great caution. Although alcohol is hydrophilic (thus water-soluble) and distributes equally throughout the body’s water content, unequal distribution to different body parts can take place – i.e. more into the blood and vitreous humor than into organs with greater fat content, like the liver. The time and intensity of consumption is also a consideration. If the decedent ingested a great volume of alcohol shortly before death, it is possible that not all ingested alcohol absorbed into the bloodstream by the time of death and after death may have stayed trapped in the stomach, from where it can diffuse to surrounding organs, leading to elevated and disproportional concentrations in these organs. For this reason, the site from where the sample for analysis was taken is also a consideration, as different sites may yield different results.

After death, postmortem processes alter and corrupt the body, among other leading to lowered pH levels. Autolysis, the self-digestion of cells, is followed by putrefaction when chemical processes further alter the body, which may lead to confusing postmortem results.

For these reasons, non-analytical evidence – i.e. history and context – should be considered in cases of ambiguous results.

Based on the history provided, it would be reasonable to assume that the decedent did not consume any alcohol before arriving at the house at approximately 02:00 on the morning of 13 August. While a depressive or “defeated” state can lead to increased alcohol consumption even among non-regular alcohol consumers, at least two friends stated that even while being anxious and depressed about her marital problems, she did not consume any alcohol at the business function and also not at the dinner they had before the three-hour flight over midnight. It is also unlikely that an airline would serve alcohol on late-night flights. In addition, existing video footage shows the decedent arriving at the house, carrying her suitcase, and that she did not appear to be intoxicated.

Perhaps the best evidence that the decedent did not either arrive intoxicated at the house or consumed alcohol between 02:00 and 05:30, is the statements by her husband (the accused). In neither his first oral statement to Officer Coonrod (which must have been between 13:40 and 14:00) nor during the interview with Detective Baumhover (which must have been shortly after 02:00) did the accused state that the decedent consumed any alcohol. However, more significantly, when the accused confessed that he strangled the decedent because he went into a rage after seeing the decedent strangling their two daughters, he also did not state that she was intoxicated at the time of their argument or of the alleged strangulation of the daughters by the decedent. On this premise, given the context, if the decedent did act irrationally (to such extent that she would strangle their children to death) mentioning during the confession that she was intoxicated, would have counted in the accused’s favour.

However, for the sake of the argument and perspective, if the decedent died with a BAC of 0.128 g / 100 mℓ at 05:00 on 13 August, and an elimination rate of 0.015 g / 100 mℓ / hour is assumed, the decedent had to have arrived at home with a BAC of 0.173 g / 100 mℓ, which is a considerable high level where subjective effects would have been evident. This is not in agreement with provided history and eyewitness statements.

On the premise that the decedent arrived completely sober at the house at 02:00 and then started to consume alcohol, based on the Mellanby effect whereby the BAC peaks after approximately one hour of consumption after which there is a fixed elimination rate of 0.015 g / 100 mℓ per hour, and that the decedent consumed wine, the decedent would have needed to consume approximately 8 glasses of wine in three hours. Apart from the fact that this would seem out of character behaviour, it would have been considerable consumption for a lean woman on an empty stomach and without developed tolerance to alcohol consumption. Her motor skills would have been significantly compromised at a BAC level of 0.128 g / 100 mℓ.

While it would be safe to include postmortem fermentation (postmortem synthesis) as the likely cause of the BAC at the time of sampling on an elimination basis, the following factors need to be considered.

If a dead body is exposed to temperatures higher than 5oC, postmortem processes will have greater potential to ensue. While cooling the body may slow these processes down considerably, even halting them, cooling does not eliminate decomposition completely. It must also be borne in mind that before the body is placed in the fridge, there is exposure to ambient temperature and also in the hours before autopsy when the body is prepared for autopsy and sampling.

In this case, in order to consider the possibility of postmortem fermentation, the two most significant variables to consider are postmortem interval time and temperature over this period. From historical weather data it appears that from the morning of 13 August until the discovery of the body (i.e. declaration of death) at 00:05 on 16 August, the temperature in the relevant area ranged from 8 to 31oC, with mostly sunny days. Given the time-lapse of 67 hours from the assumed time of death (at 5:00 on 13 August) until the declaration of death (when the body was not in cooling yet) at 00:05 on 16 Augusts, and given the average temperature of approximately 20oC (with higher peaks up to 31oC) over this period, in terms of temperature and time, conditions would have been most suitable for the rapid advancement of postmortem processes. However, whatever the conditions may have been, it is clear from the autopsy report that at the time of autopsy, generalized discolouration, bloating and skin slippage have been observed. Therefore, postmortem processes – notably putrefaction – were in progress.

For fermentation to occur, glucose and microbes (i.e. bacteria and yeast) are necessary. Glucose is prevalent in many organs of the body and the cecum is infested with bacteria, and during the postmortem process, especially under temperate conditions and in the presence of air, fermentation is very likely to occur.

Intestinal bacteria can penetrate the intestinal walls after death and can be distributed through the bloodstream via the hepatic portal vein and intestinal lymph system as long as the body temperature exceeds 5oC. For postmortem synthesis to occur, the body must be at 5oC or higher for longer than 4 hours (O’Neal & Poklis, 1996).

Although the body was buried for most of the postmortem period (until discovery), and while bodies in graves take approximately 8 times longer to decompose than in the open, the shallow grave in sandy soil would have allowed enough aeration for decomposition to advance. The thin layer of sand covering the body would have lowered the exposed temperature but it would have been considerably more than 5oC, and therefore still conducive for bacterial proliferation and the advancement of postmortem processes.

According to authoritative pathologist Bernard Knight, under the right conditions, fermentation can lead to elevated alcohol concentrations hours after death, and makes reference to a referenced case where a BAC of 0.15 g / 100 mℓ was observed in a postmortem case, where it was known that there was no antemortem alcohol consumption (Saukko & Knight, 2008).

In their article ‘Postmortem production of Ethanol and factors that influence interpretation’ O’Neal & Poklis (1994) make reference to several cases where postmortem synthesis has led to elevated blood alcohol concentrations. They make reference to a study by Bonnichsen et al. (1953), where a 3-month old infant found not more than 6 hours after death, showed significant ethanol concentration in blood, liver, kidney, and spleen – of 0.235, 0.112, 0.107, and 0.111 g / 100 mℓ respectively (this also shows how the site of sampling can yield different results). They also make reference to a study by Jones et al. (1991) where a 73-year old woman who died from a car crash, had a BAC of 0.053 g / 100 mℓ (it was reported that it was highly unlikely that the decedent consumed any alcohol prior to the crash) (O’Neal & Poklis, 1996). A review of studies of actual postmortem cases revealed that a range of 12–57% of ethanol positive cases was attributed to postmortem synthesis. When all postmortem cases positive for ethanol were surveyed, 12% were the result of postmortem synthesis (Caplan, 1990). When the cases were limited to only to decomposed bodies, the percentage rises to 20% (Zumwalt, 1984; Gilliland, 1993).

While there is no direct correlation between the in vitro cultivation of microbes and ethanol production, it is generally accepted that if no microbes are found in the specimen, the source of the ethanol is ingestion (assuming that the microbes responsible for postmortem synthesis survived long enough to be cultured) (O’Neal & Poklis, 1996). In forensic work, this is not so easy to determine as few laboratories cultivate microbes routinely. In this case, as discussed previously, the case history does not suggest antemortem ingestion.

Certain conditions may raise the microbe level, such as starvation and physical exertion, when the pH rises, leading to increased microbial proliferation and thus potentially increased postmortem synthesis.

When ethanol is absorbed from the stomach, it distributes throughout the body according to the water content of the various tissues and fluids. For this reason, the site of sampling is important to consider as the water content in different tissues varies. It is not clear why the spleen was preferred as sampling site, and although it is often routinely used as sampling site in postmortem cases, if vitreous humor were sampled, a different BAC may have been observed, as vitreous humor is more isolated (and thus less influenced by postmortem redistribution and diffusion) and contains no bacteria. The point being, that the BAC of 0.128 g / 100 mℓ at the time of autopsy, is not necessarily representative of either real ingestion or real postmortem synthesis.

Lastly, although it cannot be stated with any certainty or as fact, after sampling degradation of the sample and postmortem synthesis can take place in the test tubes if storage conditions are not adequate, or if sampling was not done correctly. For the purpose of this report and opinion it is assumed that the headspace gas chromatography method of analysis was done correctly and that the result can be trusted as a true reflection of the ethanol concentration of the sample at the time of sampling, whatever the source of the ethanol was.

Conclusion: Given the history of the unlikely digestion of alcohol prior to death, the 67 hours the body was exposed to temperate conditions, plus (to a lesser extent) the 36 hours after discovery until autopsy, and the evidence of bloating at autopsy (which suggests microbial presence and activity), it is not only possible but highly likely that fermentation and thus postmortem synthesis of alcohol could have taken place. There is no reason to exclude this possibility. A level of 0.128 g / 100 mℓ is a high BAC level, but the conditions would have been extremely suitable and conducive for the postmortem synthesis of ethanol, I order to produce said BAC.

Based on the reason explained in this report, it can be stated with a high degree of confidence that the 0.128 g / mℓ BAC was the result of postmortem synthesis in the body and/or in the collection tubes.

Additional Note: Although the decedent suffered from lupus and fibromyalgia, not enough information is known to consider the influence this may have had on the postmortem synthesis – such as the severity of the conditions and medication she may have been on, or if she had episodes of flare-ups close to the time of death (which may have aided corruption of the postmortem body). Although not entirely relevant, the expelled fetus was most likely the result of pressure on the lower abdomen due to bloating, which exerted pressure on the uterus. The manner in which she was buried (kneeling forward) would have contributed to the pressure on the uterus. It is unlikely that the fetus contributed to the BAC in the spleen as diffusion from the uterus to the spleen must have taken place, and there are various barriers to be crossed. It is also not known when the fetus was expelled, but that would likely have happened as bloating ensued (and the time of bloating would have been the most likely and prolific time of synthesis). Since the biology of a pregnant woman may be altered, the general condition of the body may have been conducive for increased synthesis, but this cannot be stated with any certainty, and therefore neither the medical conditions nor the pregnancy and presence of a fetus were deemed supplementary factors that contributed to the BAC of 0.128 g / 100 mℓ in the spleen at the time of sampling. The postmortem 0.128 g / 100 mℓ BAC due to postmortem synthesis is possible in perfectly healthy (and un-pregnant) individuals who were exposed to suitable conditions for postmortem synthesis. In this case, conditions were most suitable and conducive for the postmortem synthesis of ethanol.


Gilliland, M.G.F. & Bost, R.O. 1993. Alcohol in decomposed bodies, postmortem synthesis and distribution. Journal of Forensic Science. 1266–74.

O’Neal, C.L., Poklis, A. 1996. Postmortem production of ethanol and factors that influence interpretation. American Journal of Forensic Medicine & Pathology.

Saukko, P., Knight, B. 2004. Knight’s Pathology . 3rd Ed. Hodder Arnold: London.

Zumwalt, R.E., Bost, R.O., Sunshine, I. 1982. Evaluation of ethanol concentrations in decomposed bodies. Journal of Forensic Science. 27:549–54.

Another Triple Murder

On 27 January 2015 Martin, Teresa, and Rudi van Breda were brutally killed in their house in an upmarket security estate near Stellenbosch South Africa. Henri van Breda, one of three siblings in the family, stood trial on their murder and was convicted of their murders in 2018.

Wikipedia Background

Below is my take on the case.

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