Lividity and Rigor Mortis: Determining The Time Of Death

Determining The Time of Death

When the heart stops beating, gravity pulls blood to the lowest point in the body. Blood pooling in those low areas stain the surrounding tissue giving the appearance of bruising. This staining of tissue is called livor mortis, or lividity. For example, a victim lying flat on his back when he dies exhibits lividity on his back, buttocks, and the back of his legs. The same is true on the front of the body, if the victim is found lying face down.

Livor Mortis (lividity) can help investigators determine the time of death. The staining of tissue normally begins within the first two hours after death. The process reaches it’s full peak in eight to twelve hours.

If the victim is moved during the first six hours after death the purplish discoloration can shift, causing the new, lowest portion of the body to exhibit lividity.

After a period of six to eight hours after death, lividity becomes totally fixed. Moving the body after eight hours will not change the patterns of discoloration. Therefore, investigators know a body found lying face down with lividity on the back, has been moved.

Rookie officers have often confused lividity with bruising caused by fighting.

Remember, ambient air temperature is always a factor in determining the TOD (time of death). A hot climate can accelerate lividity, while a colder air temperature can slow it down considerably.

Rigor Mortis is the stiffening of muscles after death. The muscle stiffening (hence the use of the term, stiff) is caused by the loss of adenosine triphosphate (ATP) from the muscle tissue. Without ATP, the muscles can no longer function normally, and begin to contract and stiffen.

Rigor mortis begins in the smaller muscles of the face and neck in about two hours after death. The process then moves downward from the head to the feet. The body becomes completely stiff in approximately eight to twelve hours.

Bodies remain rigid (the rigid stage of rigor mortis) for approximately eighteen hours, at which time the process begins to reverse itself in the exact same order – small muscles first, followed by the larger ones, moving from head to toe.

In approximately twelve hours the body returns to a flaccid state.

Again, like livor mortis, air temperature is a factor that can accelerate or slow down rigor mortis. Certain poisons and illnesses can also affect rigor mortis.

Determing TOD using rigor mortis is not an exact science.

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The Morgue – Part Two

Morgue 2

Our tour of the morgue continues with a peek into the autopsy room where we’ll examine some of the tools of the trade. If your stomach holds up we’ll even have a glimpse of the star of the show, a murder victim.

The photograph above is of an autopsy station. Think of it as a pathologist’s workshop. To begin the autopsy, a body is placed on a gurney and is then positioned head first against the center, sink area of the station.

WARNING – GRAPHIC IMAGES BELOW!

Pathologists select instruments from a rolling cart.

Tools of the autopsy trade.

Bone saw used for cutting through the rib cage beneath the “Y” incision. It’s also used for cutting through the skull.

Scales for weighing organs.

GRAPHIC IMAGES BELOW!

WARNING>>>WARNING>>>WARNING>>>WARNING>>>WARNING>>>

Upper chest area of a murder victim.

Ligature mark on the neck from strangling.

Post autopsy “Y” incision sutures.

The end. Really…

 

 

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The Morgue

Morgue

Death investigations are conducted by both the police and medical examiners or coroners. Each jurisdiction determines whether or not they have a coroner or medical examiner. A coroner is an elected official and may or may not be a medical doctor. A medical examiner is a medical doctor that has been hired by a city or county to conduct autopsies and investigate the cause of suspicious deaths.

The police are in charge of all murder scenes, but medical examiners and coroners are in charge of the body. Medical examiners and coroners do not interrogate suspects and detectives do not examine bodies.

Bodies are placed in body bags and delivered to the morgue in specially equipped vehicles.

Bodies are placed on gurneys and rolled onto scales where they’re weighed.

After weighing, the body is placed inside a cold room until autopsy. Black or dark gray, leak-resistant body bags are used  pre-autopsy. The paper bag resting on the body of the murder victim at the top of the photo contains the victim’s personal belongings.

Cold rooms also store amputated body parts. The gray trays on the right contain severed limbs. White, paper-like body bags, like the one lying on the gurney in the rear of the cold room above, are used post-autopsy for bodies waiting to be transported to funeral homes.

Don’t forget to stop by on Saturday and Sunday for The Weekend Road Trip

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