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Subject:
Forensic medicine electrocution
Category: Science > Biology Asked by: curiousk-ga List Price: $15.00 |
Posted:
06 Mar 2003 16:58 PST
Expires: 05 Apr 2003 16:58 PST Question ID: 172938 |
I'm working on a murder mystery, and I need to know how the effects on the human body of electrocution when an appliance is dropped in bath water are different from the effects of electrocution when a person comes into contact with power lines. During an autopsy, could a medical examiner tell the difference and how? |
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Subject:
Re: Forensic medicine electrocution
Answered By: tutuzdad-ga on 06 Mar 2003 21:00 PST Rated: |
Dear curiousk-ga; Thank you for allowing me an opportunity to answer your interesting question. The answer to your question is, yes, a medical examiner could tell at autopsy whether or not someone has died as a result of electrical shock from an appliance in the bathtub as opposed to having contacted a high voltage utility wire. The interesting thing though is that this is often something that is apparent to an observant person who was well educated in death investigation. In my 22 years in law enforcement, I have witnessed autopsies, known many coroners, paramedics and medical examiners, and I have personally investigated deaths caused by a wide variety of circumstances. I have also been trained in death investigation and could probably tell, in most situations whether or not someone died as a result of such a scenario or had been strategically placed in the position in which they were found following their death at another location by other means. One of the initial methods of coming to this conclusion is to determine whether the circumstances are consistent with the marks or damage to the body. Then, and most importantly, is to determine, through comparison, whether or not the body in question bears evidence that is consistent with characteristic marks, damage or evidence to that has been documented in known cases. Both of these will be instrumental at autopsy, as you will see, in determining the actual cause of death. First, lets talk about the circumstances. Obviously, at death, the body ceases to function. The heart stops, breathing stops and brain activity comes to an end. This means that the heart no longer sends blood to the lungs; therefore the blood is no longer being renewed. Because the lungs are no longer functioning, air ceases to enter the lungs allowing for room for other extraneous material, such as vomit or bathwater to fill them. The amount of time the blood has been without oxygen can be determined in a number or ways, one of which is the level of coagulation, which occurs at a relatively predictable rate. Cells can also be examined to see if the blood is contaminated with bacteria from extraneous material, indicating that, for a while at least, the body was attempting to breathe while submerged. If this is the case, the small blood vessels (capillaries) in the lungs and brain will have ruptured. Upon physical examination, this is also apparent in the eyeballs. These types of things will not, in themselves, indicate a cause of death, but can support the suspicion that the victim was in the bathtub at the time of death. Now, lets talk about what electrical shock does to a human body. When electrocuted, a living normally dies from asphyxiation. This is caused by the instantaneous cessation of breathing and heart activity. The effect of the shock can be compounded by moisture, the weather, the surroundings and how long the body was exposed to the current. In a situation where the body continues to be exposed to the current long after death, the resulting damage can be enormous. One of the characteristics of electrocution is Joule marks (also called Joule burns). These are entrance and exit wounds caused by the current as it passes into and out of the body. If electricity does not pass completely through the body, a serious shock can occur, which may cause critical localized burns but is not always fatal. In electrocution, the current passes into and out of body leaving grayish, puckered wounds on the skin where this occurs. If the current is a household current, such as a 110, 220 or 240 volt current, the wounds are not as prominent, but when much higher voltage is the cause of death, the Joule burns will be tremendous, often causing remarkable injuries at the point of entry and exit, usually taking on the shape of the item carrying the current. In addition, high voltage will often burn through the body, damaging all the tissues through which it passes, destroying it, and in some cases be especially traumatic, shattering the bones near the point of exit. It would not be uncommon then to see someone who had touched a high powered utility line with his hand to have a fairly gruesome wound to his hand, but a devastating wound or even an amputation of his foot where the current exited. This would not be the case with a household current, even though it would be equally deadly to a person in a bathtub. It should also be noted that a large current would probably throw the person away from his present position, making exposure relatively brief, while an appliance dropped in a bathtub would hold the body captive as the water itself became a conductor of the electricity, and exposure time would be much more sustained, perhaps causing large blistered areas but not the devastating wounds typical of a much greater current. High voltage exposure might also burn off the hair, or cause the eyes, torso or limbs to burst. These wounds would not be considered characteristic of lower voltage electrocution. Higher voltage typically electrifies jewelry causing significant secondary burns where these meet the skin. The tissues in the proximity of a necklace, watch or ring will also be severely damaged in many cases. This is not characteristic of a lower household current either. Finally, as the blood in the body coagulates, it tends to run to the path of least resistance, usually the lowest portion of the body or those portions that are in contact with a surface. That is to say that the blood pools up in the back if a body is supine, or in the face, chest and abdomen if the body is face down. This gravitational pooling of blood, called post-mortem lividity, is deep purple in color (or black if the person has been there long enough for the pooled blood to decompose) and very closely resembles a bruise. If a body if found sitting slumped in a bathtub for example, upon examination one would expect to find pronounced lividity in the back, buttocks, rear thighs and heels of the feet. If this is not present, or lividity if present in areas that are not in contact with the bathtub, it would give rise to the notion that the body may have been placed there after the fact. Below you will find that I have carefully defined my search strategy for you in the event that you need to search for more information. By following the same type of searches that I did you may be able to enhance the research I have provided even further. I hope you find that that my research exceeds your expectations. If you have any questions about my research please post a clarification request prior to rating the answer. Otherwise, I welcome your rating and your final comments and I look forward to working with you again in the near future. Thank you for bringing your question to us. Best regards; Tutuzdad-ga INFORMATION SOURCES (CAUTION: Some photos and text found in these links are graphic. They are not intended to be viewed by those who might be easily disturbed by these topics.) DEATH INVESTIGATION http://www.llcc.cc.il.us/justice/investigation/homicide.html MURDER BY ELECTRICITY http://www.fortunecity.com/tattooine/williamson/235/sicd016.html AFRICAN NEWSLETTER http://www.occuphealth.fi/e/info/anl/395/kitumb.htm POSTER SESSION http://anil299.tripod.com/vol_002_no_002/poster/poster001.html TIME OF DEATH http://www.dundee.ac.uk/forensicmedicine/llb/timedeath.htm#Lividity SEARCH STRATEGY SEARCH ENGINE USED: Google ://www.google.com SEARCH TERMS USED: "HIGH VOLTAGE" LOW VOLTAGE" ELECTROCUTION DEATH INVESTIGATION SHOCK DEATH BATHTUB ELECTRICAL DEATH BATHTUB ELECTROCUTION FORENSIC ELECTROCUTION AUTOPSY ELECTROCUTION |
curiousk-ga
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Wow! Your response was very thorough and gave me a solid indication of how to edit my story. Your knowledge and experience were very valuable, and your answer fascinating to read as well. Thanks so much. |
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Subject:
Re: Forensic medicine electrocution
From: aceresearcher-ga on 07 Mar 2003 05:19 PST |
curiousk, Does your plot involve disguising a high-voltage electrocution death as death by appliance in bathtub, or vice-versa? Depending on which idea is being used, there are some considerations which may help advance your plot. Regards, aceresearcher |
Subject:
Re: Forensic medicine electrocution
From: curiousk-ga on 07 Mar 2003 07:37 PST |
In response to your question, my plot involves disguising death by appliance in bathtub as death by high-voltage electrocution. I'd appreciate any input that might help make the plot more credible. Thanks for your interest. |
Subject:
Re: Forensic medicine electrocution
From: aceresearcher-ga on 07 Mar 2003 14:20 PST |
Greetings, curiousk! In addition to being an avid reader of murder mysteries and nonfiction forensic pathology books, I am fortunate enough to be on quite close speaking terms (most days) with a pathologist, and, out of interest, we sat discussing your Question for awhile last night. If you are going to make a habit of killing people off with your literary endeavors, I recommend that you consider purchasing one of the professional bibles, Spitz & Fisher's Medicolegal Investigation of Death. This is an excellent source for details of various methods of demise, and in addition to serving as a technical reference for accuracy, you may find it a good place to get ideas for dispatching your victims in future tales of mayhem. http://www.amazon.com/exec/obidos/tg/detail/-/0398058180/102-8129652-6836169 Farther on when I attribute quotes to Spitz & Fisher, this is the source to which I am referring. Bathtub appliance electrocution disguised as high-voltage electrocution makes your job a little bit easier than it would be the other way around. As tutuzdad has said, high-voltage electrocution nearly always leaves severe burn evidence (as compared to lightning strikes, which may leave severe burn evidence or barely any evidence at all). So, the problems that your murderer is going to face in covering up his/her crime include: 1) Pruning - live skin, when exposed to water for any length of time, starts to develop little wrinkles (pruning). If a person dies with the skin in this state, it will not disappear posthumously. So for your killer to be successful with their misdirection, the electrocution death by appliance must occur shortly after entering the water to avoid prominent pruning artifact after removal of the body from the water. 2) "Postmortem Lividity (Livor Mortis) - Cherry-pink livor is also seen in bodies recovered from water... Humidity prevents the escape of oxygen, allowing for an excess of bright red oxyhemoglobin in the skin." [Spitz & Fisher, page 24.] So your murderer needs to get that body out of the water and dried off as soon as the electrocution has been accomplished, to prevent the livor from being uncharacteristically pink for an out-of-water, high-voltage electrocution (unless the body is to be found in a pool of water underneath a high-voltage power line). 3) Postmortem Lividity (Livor Mortis) - as tutuzdad describes above, after death the blood in the body will pool and coagulate at the lowest gravity points in the body. This means that the murderer must get the body arranged as soon as possible after death in whatever position they want the body to be found, so that the lividity will correspond to the position in which the body is discovered (or they will have to be sure to position the body consistent with the livor once they bring it to the desired scene of discovery). If the lividity develops while the body is twisted up in the trunk of a car, this may be a hard feat to accomplish. 4) Trace evidence - in cases of suspicious or non-natural death, the forensic investigators will frequently collect minute and microscopic samples such as hairs, fibers, and dirt. In the case of your hapless victim, the existence of excessive trace amounts of soap product on the skin must be avoided. This also means that the murderer will not want any of their own scalp or facial hair, or fibers from the bathroom carpet, hanging around where they deposit the body. Furthermore, in addition to being able to obtain fingerprints from solid objects such as buttons, eyeglasses, belt buckles, and shoes, investigators have developed technology to sometimes retrieve fingerprints from skin, so your murderer had better be wearing gloves while they're doing their dirty work. 5) Burn evidence - "one-third to one-half of low-voltage electrocutions have no electrical burns" [Spitz & Fisher, page 521, footnote credited to Wright, R.K., and Davis, J.H.: "The investigation of electrical deaths: a report of 220 fatalities", the Journal of Forensic Science, 25:514, 1980.] This means that your murderer is going to have to come up with a convincing way to run a high-voltage current through the body to achieve the appropriate burn marks; just placing the body beneath a high-voltage power line is not going to do the trick. 6) Tissue evidence - furthermore, the high-voltage blast to the corpse needs to take place as soon as possible after death, because gross [visual] and cellular [microscopic] effects on a live person's tissues will differ from those on a dead person's tissues. The murderer had better hope that the medical examiner does not take too many cellular-level samples, nor examine them too closely. (However, it is quite likely that in the face of overwhelming evidence of high-voltage electrocution, a medical examiner will make their determination solely on the basis of the gross evidence and not examine cellular evidence). 7) Scene evidence - murderers attempting to cover their crime by moving the body and/or attempting to change the apparent cause of death frequently screw up in making sure that all the evidence is consistent with their carefully-constructed scenario. Sometimes clothing is put on a body improperly, the wrong clothing is put on a body, or an important article of clothing (such as underwear) is omitted. Fractures and contusions must be consistent with the size of the fall, if the body takes one. If the body has supposedly fallen 50 feet, it had better show some serious impact damage. In addition, is the murderer going to leave the victim's car at the scene of discovery, or provide some other plausible physical means for the victim to have arrived there? 8) Psychological evidence - don't forget that if the death is to be considered an accident, the victim will need some sort of plausible motivation for being at the scene of the discovery as well (although a secret assignation with a murderer at the site of the high-voltage lines would do, if your murderer's goal is merely to cover up just the method of murder and not the fact that it WAS a murder). I hope that this information assists you in creating the best murder mystery possible! Regards, aceresearcher |
Subject:
Re: Forensic medicine electrocution
From: curiousk-ga on 09 Mar 2003 13:00 PST |
aceresearcher, thank you to you and your pathologist friend for all your input. Also, thanks for the heads up on the reference book. I plan to follow-up. To address the points you raise, my plot does include removing the victim from the water immediately after electrocution, so we avoid some of the problems you raised such as skin pruning. The murder does dress him and transport him, but the murder site is close to the site of the high voltage electrocution. Although it's impossible to remove all trace evidence, because the murder occurred in the victim's home, you would expect his leavings in the bathroom and trace evidence from the home on him to a certain extent. On the other hand, if there's no evidence at all, there's no way to catch the murderer. The method of high voltage electrocution is a bit of a locked-room mystery, so I'm not trying to suggest accident, just draw attention away from home and focus it on work. He gets caught up in the transmission lines coming into a substation. How? Well, I can't give it all away! Thanks again. I hope you guys are having as much fun as I am. |
Subject:
Re: Forensic medicine electrocution
From: tutuzdad-ga on 09 Mar 2003 15:01 PST |
A carefully selected rainy night would account for some of the water-logging, but the wounds caused by the high-voltage after death might be discernable since the body responds differently to post-mortem damage than when the victim is alive. To render the victim unconscious with a bathtub shock, transport him and then electrocute the dickens out of him at the scene would likley fool anyone. As for the scene at the house, this would probably be checked even though nothing pointed to the house as the scene of the crime. A hotel would do much better. If the victim bled at all in the tub as a result of the bathtub injuries, this can be fairly easily detected using luminol http://www.deakin.edu.au/forensic/Chemical%20Detective/Luminol_test.htm sometimes even after cleaning with bleach and often, if left uncleaned or barely cleaned, years after the crime. A hotel room would take care of this since it provides the same opportunity is a tub other than his own - which would certainly be looed at. In addition, an appliance in the bathtub would short out the house current or at least trip the breaker switch. This might alert neighbors or cause irreparable damage, delaying the movement of the body. In a hotel, it might do the same thing, but no one will know where it is coming from. Regards; tutuzdad-ga |
Subject:
Re: Forensic medicine electrocution
From: curiousk-ga on 10 Mar 2003 09:16 PST |
You guys are almost too good. If I don't leave some evidence, how will the detective ever catch the murders? |
Subject:
Re: Forensic medicine electrocution
From: tutuzdad-ga on 10 Mar 2003 11:40 PST |
Perhaps a wise coroner or medical examiner might notice that no natural creasing of the skin occured where elastic bands normally bundle the outer layer of flesh. This might indicate that the clothes were placed on the body after death. Adding that the pants pockets were bundled up against each thigh and hip as opposed to being fully expanded might also lend suspicion that the clothes were put on by someone other than the victim. Perhaps a watch was inadvertently placed on the left wrist of the left-handed victim by the dressing killer (left handed people normally place their watch on their right wrist) who was left-handed himself and did it on instinct. Perhaps the killer, while dragging the body, badly scraped the back of the corpse with his metal zipper tab, indicating that the body had been placed there by someone else. This post-motem "wound" also corroborates this theory. Laboratory exam of the suspect's pants might also confirmm this if microscopic tissue from this victim is found on his zipper tab. A good way of telling if a body has been dragged is to look at the heels of their shoes. Killers in a hurry dong carry their victim, they drag them - especially if they are heavy. But your guy...he's smart. He takes the shoes off before doing the dragging. What he didn't count on is that fibers from his vehicle carpet would become inbedded in the heels of the victim's socks. He replaces the shoes on the victim's feet at the scene, thereby protecting the trace evidence for future discovery and the smoking gun against him. Oh, another thing about shoes...people tie their shoes from "behind" them (while they are on their feet. A comparision of how the victim's shoes are tied with shoes at his house that have been slipped off his feet while tied would also suggest that someone else might have tied his shoes. Search a bit more about this by looking up "forensic knot" in a search engine. The info kinda cool if this sort of investigative approach appeals to you. It can also tell which primary hand the killer uses (left-handed people have certain common tying characteristics that right handed people don't have.) Dragging can also seperate or dislocate the shoulders. This might be explained by the sudden jolt of high voltage, but not as an post-mortem injury. If the victim was alive when this happened there would be bleeding or bruising in the shoulder cups (joints), but mysteriously, none is found, suggesting the injuries are post-mortem. Other things might be, hearing aid in the wrong ear, hair parted on the wrong side, contacts are not in the eyes (victim always wears them), victim religously takes insulin shots at 7am daily, but no drugs are found in the body, suggesting that the victim might not have been killed at noon, but much earlier in the day. Tie these things in with your story to make them fit other evidence that point to your killer. Regards; tutuzdad-ga |
Subject:
Re: Forensic medicine electrocution
From: curiousk-ga on 10 Mar 2003 12:41 PST |
I've been thinking the past couple of hours about the last set of comments regarding trace evidence being left by the victim at the scene of the crime. I understand your point that it would be impossible for the murderer to eliminate all evidence, but if the crime scene is the victim's own bathroom, wouldn't you expect to find clothing fibers, blood and other leavings there even if no crime had been committed? I can see if he bled profusely the killer would have a problem, but if it's a matter of a scrape as he is dragged out of the tub, for example, wouldn't it be hard to prove that the blood was related to the murder? I did review your other comments, though. I think you've offered some great ideas, especially about the shoes. I wonder if it would occur to an investigator to check some of the other clothing evidence before he realized that the victim must have been killed before he hit the high voltage wires and, therefore, that someone is trying to cover up the actual cause of death. |
Subject:
Re: Forensic medicine electrocution
From: tutuzdad-ga on 10 Mar 2003 13:52 PST |
If the killer shouldn't normally have fibers from the victim on his person, this would be significant. If the victim is, say, the spouse of the killer, it might not be. However, if the post-morten scrape on the victim's back is matched to the tab of killers zipper, or anything of the killer for that matter, the evidence would be damning. How could he explain anything in his posession that would have caused an injury to this body after the death occured? See what I mean? This places him at the scene of the crime. As for the clothes and the investigator - well, that depends on how sharp the investigator is. It would certainly cross "my" mind, if that's what you are asking. On the other hand, many people have gotten off scott-free because no one asked the right questions - so yes, it's possible, but in this age of high-tech training, its probably unlikley that this would be overlooked. tutuzdad-ga |
Subject:
Re: Forensic medicine electrocution
From: curiousk-ga on 25 Mar 2003 08:31 PST |
Thanks to everyone for your help with my questions regarding my short story. I've got a draft complete now and will be shopping it around for publication. If those of you who commented would like to read a draft, I'd be happy to share. Thanks again. |
Subject:
Re: Forensic medicine electrocution
From: aceresearcher-ga on 25 Mar 2003 09:00 PST |
Thanks for the offer, curiousk! Researchers are not permitted to have personal contact (such as e-mail) with Customers; however, if you have your story available on the web, please post the URL here in a Comment, and I would be delighted to read it! Best wishes, aceresearcher |
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