Showing posts with label diving. Show all posts
Showing posts with label diving. Show all posts

Monday, February 3, 2014

Police Dive Teams - How to Find People and Evidence Under Water: Information for Writers


Oxygen toxicity occurs when the lungs take in ...
 (Photo credit: Wikipedia)
Last fall at the Writers' Police Academy, I attended a seminar in how the police dives for evidence and conducts searches for bodies that are underwater.

The divers that we interviewed were all police officers; they trained on a regular basis as a water recovery team. When a need arose, they would leave their normal workday duties and dive.

These divers were involved in cases that included:
* Evidence recovery
* Submerged body recovery, including:
   `victims of a crime

Teams might also participate in:
* Inspecting the hulls of ships in
   anti-narcotics operations
* Explosive Ordnance Disposal (bombs)
   in anti-terrorism efforts

The team that I interviewed maintained a minimum of three dive members per event.
* A below water surface diver
* An attendant diver who stayed on the surface to assist the underwater diver and to signal/communicate
* A supervisor who works on the surface to direct the operation

Video Quick Study (6:05) Norfolk, England but this is the same information that we received.

Most of the diving investigations are done in highly hazardous environments which might include
* Cold temperatures
* Zero visbility
* Contaminated waters including chemical hazards
* Sharp objects that the divers must feel with their hands since they can not see
* Entanglement and entrapment objects such as submerged trees, rocks, and debris

Video Quick Study (3:32) What it looks like under there.
Video Quick Study (8:21) Difficulties of suiting up, moving, and seeing underwater.

This is picture of one of our instructors, "Cookie." Cookie's technique for keeping the heebie-jeebies at bay while he's groping through pitch-black water for a dead body includes singing as loudly as he can. That's why he makes extra bubbles.

Video Quick Study (3:34) includes information on equipment, sonar, finding a car

US Navy 090628-N-5710P-319 A U.S. Navy diver c...
 A U.S. Navy diver conducts a dive supporting Infinite Response 09, a bilateral exercise between the U.S. Navy and the naval forces of a Middle Eastern country (Photo credit: Wikipedia)
The team might be called to investigate:
* Natural water ways such as oceans, rivers,
   and ponds
* Dams
* Caves
* Sewage ponds - there's a nasty plot twist for

In some cases sonar is used to reduce diver exposure. This includes side-scan sonar and radial sonar. The sonar can help locate:
* Vessels
* Vehicles
* Planes
* Bodies
* Evidence

Search Patterns:

graphic from Wikipedia

Arc Search

* Also known as a pendulum search and a fishtail search
* The diver has a rope that is fed to him by his attendant diver.
* The diver will start on one side of a designated line (such as a shore
    line) and swim/grope through the water at the far reach of the line.
* At the end of the arc, the diver turns to go back the other way. The
   line is then released at a measured increment, knotted to maintain
   a record, and fed to the diver. For example: if the diver is looking for
   a bicycle the attendant might release a foot and a half of slack between
   arc rotations. If it is a gun, the arcs are much tighter.
* Once the diver has searched the area that can be conveniently reached
   with the rope line, the center point is moved to search another area. 
* This search works best when the general area is known.

graphic from Wikipedia

Circular Search

If the team was out in the water, away from a shore line, they would use a circular grid pattern.

This operates in a similar way as the arc search.
* Fixed central point
* Diver swims 360 degrees before his line is 

Other Search Patterns

* Jackstay - Has divers swimming a straight line along a shore then moving out a length to swim another
   straight line.
* Snagline - When an object is large enough, like a car or fridge, a line can be held in parallel swimmers'
   hands so that it will catch on the item.

English: An Engineer-Diver with KB Bandmask
 (Photo credit: Wikipedia)

Underwater communication 

Can take place via
* Line signals 
* Communicators

Once an Object is found

* The diver sends up a signal marker
* The GPS coordinates are documented
* The item is elevated using air balloons

Video Quick Study (2:21) You can see the lift bags bringing up a car.

A Body 

* Does not lay flat on the floor of the water. The upper half is held at an angle buoyed by air trapped in the
* Will float after about seven days as the body fills with gases
* After several more days as cavities are punctured by fish, birds, and other animals, the body will sink back
   into the water.
* The rate of decomposition depends mostly on water temperatures. The colder the water, the longer the
   body will remain intact.
* The deceased is bagged underwater.
   `This is for the sake of the survivors watching from shore
   `This helps to maintain any evidence that will help investigators

Video Quick Study (2:26) Divers talk about their experience and shows arc, and signalling.
Video Quick Study (3:29) Canadian and American divers certify in ice diving. YIPES! 

Video LONG Study (47:00) If you are writing a SCUBA scene you may want to spend the time learning 
                                about the problems of hypothermia, dry suit, and choices.

Thank you so much for stopping by. And thank you for your support. When you buy my books, you make it possible for me to continue to bring you helpful articles and keep ThrillWriting free and accessible to all.

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Friday, November 22, 2013

Yup, I'd Say He's Dead All Right: Algor, Livor, and Rigor for Writers


Grave (Photo credit: howzey)
WARNING - this article contains photos of bodies that might be considered graphic or disturbing. Please be aware of your comfort level before reading his post.

Excerpt - CHAIN LYNX

     "Wilson wanted to make sure that he was long gone, and the body was in bad shape when it was found?”
     Deep snorted. “Bad shape, that’s an understatement.”
     “How so?” I asked.
     “It didn’t take the week to find the corpse. The heat in his motel room was on full blast, and they smelled the body from the lobby.”
     “Oh, Gross!”
     Deep waggled his brow. “I’m glad it wasn’t my job to pour him into a bag."

Here's a Video Quick Study (6:11) which humorously goes through the normal steps of what happens from death to interment.

Death is not a pretty sight. It doesn't resemble the Hollywood and television deaths or the deaths often portrayed in literature. There is a series of events that take place. Before we take a quick look at three aspect of decomposition -- algor, livor, and rigor -- let me just address three little sniggly bits. 

1. Urine and Feces - Urine and feces will only leave the body if the bladder or bowl was full.

    The sphincter muscles containing the waste matter relaxes, as do all of the muscles, no longer holding the
     contents inside. If the person has been in the process of dying over many days then they probably have
     not eaten or been hydrated and there is nothing to evacuate. If it is a sudden death, but the person has
     just relieved themselves, they will not eliminate at death.

   "The woman’s lifeless body collapsed like a heap of dirty laundry in front of the door. Urine pooled out from under her." ~ Missing Lynx

Eye death
Eye death (Photo credit: @Doug88888)
2. They close their eyes -Closing one's eyes, as well as
     holding the mouth/jaw shut requires engaged  muscles. At
     death the eyelids will be half open and the jaw will be open
     and off-side. According to my daughter who is a telemetry
     nurse, the mouth slacks and drifts to the side.  
3. Frequently as death approaches the individual will go into a 

    coma or a coma-like state or they become agitated and 
    delusional. From speaking with nurses and hospice workers,
    there is no last second confessional. They go into a state of
    flux, and they expire.

Death is the cessation of all metabolic activity and functions.

1. Legal death can be reversed.
2. Biological death cannot be reversed.

WHAT DOES OCCUR POST MORTEM? How long has this person been dead?

* Breakdown happens because of the lack of body function and an increase in bacteria

   (and other organisms such as bugs).
*  How quickly the body breaks down is largely a function of temperature. 
*  The colder the temperature the slower the chemical changes that breakdown organic matter.
    The cold temperatures also retard organisms such as bacteria and bugs

Video Quick Study (1:08) 5,000 yr old man found frozen in a glacier. The body is amazingly intact.

These changes overlap in time:

Algor Mortis - 

English: Al Gore's Hearing on Global Warming
Photo credit: Wikipedia)

NO! That's Al Gore. We're talking about ALGOR mortis when the dead body cools. 
   * The body loses 2 degrees C. in the first 2 hours and approximately
      1 degree per hour after that. How cool the body gets depends on the ambient temperature.
   * Glaister Equation.Link to formula This is most accurate in a temperature controlled environment.
   * The fatter you are the more you store heat (faster decomposition)
   * Temperature of the body at death also increases decomostion. Did they have a fever? Had they just run
       a marathon?
   * Clothing - More clothes trap more heat.
   * Ambient temperature
      Video Quick Study (5:09)

2. Rigor Mortis - 

   * Rigor mortis first appears approximately 1-2 hours after death. 
   * Progressive stiffening occurs for approximately 12 hours,
      persists for approximately 12 hours, then
      diminishes over the next 12 hours as tissues break down as a
      result of autolysis and putrefaction.LINK
   * Because rigor mortis is a chemical reaction to ATP and has to
      do with shortening the muscle, it is
       interesting to note that in someone who has been physically
       active - fighting or running over a period of
       time - the rigor mortis will set in more quickly.

Video Quick Study (0:48) the difference between cold stiffening and rigor mortis
Video Quick Study (3:10) talking about Michael Jackson and rigor mortis

Livor mortis Deutsch: Totenflecke
Livor mortis Deutsch: Totenflecke (Photo credit: Wikipedia)
3. Livor Mortis - 
   * There is no longer a functioning circulatory system so
      the blood settles where gravity takes it and is seen
      as purplish on the surface of the skin.
   * If an object is laying below the body, such as a
      weapon, it could show up as a lighter spot on the
   * Darker skin makes this harder to see.
   * This takes place for about 8 hours. After 8 hours the
       blood no longer moves even if the body is turned
   * Skin color might provide information about the cause
      of death. For example cherry red is associated with
      carbon monoxyde poisoning and pink is an indicator
      for cyanide.
   *  Marbling may develop with the delineation of the
       vasculature as a result of the reaction of hydrogen
       sulfide produced by bacteria with hemoglobin from the
       lysis of erythrocytes, as shown belowLINK

Marbling outlines the vasculature in this decedentMarbling outlines the vasculature in this decedent as the postmortem interval lengthens.
 4. As the body continues to decompose
    * bacteria increases and produces a gas. 
    * The body might bloat from the gases esp. in the abdomen. It 
       can bloat to the point of bursting. This
       bloating brings bodies to the surface of the water if the person
       drowned or a body was dumped. According to Cookie, a 
       recovery diver who spoke to us at the WPA, the body will float
       around the seventh day and will descend again once the fish,
       birds, etc. who are eating the body poke a hole in the
       tissue allowing the gases to escape. 

See how this article influenced my plot lines in my novella MINE and my novel CHAOS IS COME AGAIN.

Thank you so much for stopping by. And thank you for your support. When you buy my books, you make it possible for me to continue to bring you helpful articles and keep ThrillWriting free and accessible to all.