Crime scene investigators are about to get a helping hand from our ancient ancestors. The earliest known synthetic pigment, Egyptian blue, is found in some of the paint on ancient statues, coffins, tomb walls, and amulets. Most other pigments long ago faded. Modern scientists, intrigued by its longevity, worked out Egyptian blue’s chemical composition decades ago. Recently it was discovered that it emits near-infrared radiation when exposed to certain kinds of light. Basically: it has rare, invisible luminescence.

And why does that help crime-stoppers? Egyptian blue can be dusted onto complicated surfaces where fingerprints are normally hard to retrieve. The surface is then photographed with a modified camera and a filter sensitive to Egyptian blue’s near-infrared rays. If fingerprints are there, they glow clearly in the resulting image. Science is amazing.

Age progression is the process of modifying a photograph to give the effect of ageing in appearance. It’s often used to aid the search of missing children. The artist scans the image of the child, and develops it using age-appropriate pictures of bloodline siblings and parents. Another way of adding family traits is using a drawing software. 

These images compare the age progression of missing children with actual photographs of them after they’ve been found. 

An autopsy photograph showing multiple flesh wounds caused by a shotgun blast. Unlike other firearms, shotgun shells usually contain multiple small projectiles that expand and spread after the gun has been fired; when flesh contact is made, the projectiles leave multiple, pitted holes rather than a single deep entry wound.

Autopsy photograph showing a bullet entry wound surrounded by a reddish muzzle stamp, or “ring abrasion”.

When a gun is fired from close range, gas forcefully enters the upper skin layers and pushes back out towards the muzzle, rupturing the cells around the bullet wound. Often this leaves a clear imprint - or stamp - that can help investigators determine the position of the shooter, the trajectory of the bullet, and the calibre of the gun.

An autopsy photograph showing the entire muscularity of a human tongue.

The person whom this tongue was excised from was a victim of a fatal house fire. Notice the sooty colour and vivid red discolouration- telltale signs the victim died from smoke inhalation

Decomposition Stain

When a body has been lying in the same place for a certain period of time (usually between 2-3 days in most cases) the blood vessels in the body start to break down and rupture, causing vapors to build up inside the major cavities. The decay of haemaglobin in the blood gives the corpse a greenish tint, while gas build up causes the skin to slip from the muscle structure or tear from internal gas pressure. After four days, the body begins to bloat enourmously, with body fluid leaking out of every orifice.

The result is a brownish stain that grows bigger as more fluid breaks down inside the body. The smell attracts copious amounts of insects, and by the fifth day the body will be host to thousands of maggots (in a room temperature environment).

2

Between 1984 and 1985, a ruthless serial killer that became known as the “Night Stalker” instilled fear into the hearts of Southern California residents. He entered homes at nights where he would dispose of any men in the house before sexually assaulting, and quite often killing, the women and ransacking the house. Age was of no consideration to this ruthless killer: he raped and killed children and he raped and killed decrepit elderly ladies. Not following much of a particular modus operandi, he used a wide variety of murder weapons. He slashed throats, he bludgeoned, he shot, and he stabbed. On one brutal occasion, he gouged the eyes out of one of his victims.

The downfall of the Night Stalker commenced after the August 25 murder of Bill Cairns and the sodomy of fiancee, Inez Erickson. As he was fleeing, a neighbourhood boy spotted him and reported him to the police, taking down the registration number of the car in which he fled. Three days later, the aforementioned car was discovered discarded in Los Angeles. A run of the registration confirmed that it was a stolen car. The car was delivered to the Orange County Sheriff’s Department where it would be vehemently combed for evidence. 

Chemical fumes were pumped into the car and as a result, hidden fingerprints reacted to the fumes and turned white. After the fumes dissipated, the fingerprints were investigated with a high-power laser ray. The fingerprints were then analysed and flown to Sacramento, where an Automated Fingerprint Identification system had just recently been installed. The fingerprints uncovered from the car were run against the database of previous offenders.

Moments later, they had a match: Richard Ramirez.

The footprint that caught Richard Ramirez. At the time, Ramirez bought a new pair of shoes that were extremely unique and rather easily traceable. Were it not for this footprint, Ramirez might have still been killing to this day.

Sex Differences in Human Skeletons

Even with the aid of modern technology it can still be relatively difficult to determine the sex of a recovered skeleton, particularly if the remains are incomplete or don’t represent an adult. However, there are a few reliable indicators of sex present within a human skeleton, the most obvious of which can be found in the skull.

1. Shape of lower jaw

Males tend to have a much heavier, squarer jaw than females. The bone structure of the lower mandible is much thicker and stronger.

Females tend to have more delicate, rounded lower mandibles with the chin featuring a prominent point.

2. Shape of eyes

Males have much deeper, sturdier orbital sockets with a prominent shelf of bone extending across the brow.

Females have rounder, more widely spaced orbital sockets with no brow bone.

3. Shape of nasal cavity

Males have a pear shaped nasal cavity

Females have a teardrop shaped nasal cavity

4. Size of skull

Males typically have larger, heavier skulls than females and have considerably more bone structure around the jaw, brow, and back of the head.

Female skulls are smaller, more round in shape, with noticeably soft bone structure and a much smoother overall texture.

(Picture represents a male skull on the left and a female skull to the right)

“[bite marks] are indicative of a highly enraged and sadistic killer who could potentially escalate to more extensive mutilation or cannibalistic rituals in future homicides.”   (from “The Method and Madness of Monsters”).

Pictured above is the bite mark of Canadian serial killer Peter Woodcock which was found on the bottom half of the leg of his very first victim, 7-year old Wayne Mallette. Woodcock was 17 years old at that time.

The Importance of the Autopsy

There is a lot of misunderstanding about autopsies out there– who gets them, how they’re done, and what their purpose is. I’ve often heard the question (not necessarily directed at me, but to forensic pathologists) “Why does this person even need an autopsy?” And sometimes it can seem silly. If someone has a big stellate gunshot wound through the middle of their forehead, it’s pretty easy to guess what they died of (though of course there’s the possibility it was inflicted post mortem). Or with very obvious accidents, doing an autopsy may seem like a waste of time and resources.

It’s still typically done.

I could list many reasons why this is (and I’m sure in the future I will), but I want to illustrate this concept with a scene. This is not identical to something I have seen (I don’t discuss those details online) but it’s close and typical enough that it could be, and it probably is a case of someone out there. And that’s the point.

Anyways.

This particular decedent died in his own backyard, right next to a ladder that had clearly fallen over. He appeared to have been repairing his roof. Now, while the immediate assumption is “he fell off the ladder,” other possibilities do need to be considered. Was he pushed (making it a homicide)? Did he have a medical problem, like a heart attack, that caused him to fall? These are things you, the death investigator, have to ask yourself. But based on the scene investigation you are fairly confident that it was a simple accident. The series of events seem clear: man climbs up ladder, man falls off ladder, man dies.

You might be expecting me to say that you’re going to discover something shocking during the autopsy that challenged your expectations; poison in his blood, or something like that. Rarely, that does happen. But in this case, you find something with a different set of implications.

The medical examiner does agree that this was an accident. There are no signs of wrongdoing, and there are no clots in his brain, arteries, or veins that would have caused a sudden natural death.

But his veins and arteries are seriously occluded. The worst you have seen in any person who did not die from cardiac complications. One of his heart valves is also about four times the size it should have been. It is very quickly apparent that this man, someone in his early 30s at his death, would not have survived another few years in his condition. When you see such significant heart disease in someone so young, it is almost always genetic in nature.

There are far reaching implications here, aren’t there? This man has three children, who are now going to be screened for genetic heart disease. If caught early, there are medications that may allow them to manage their conditions somewhat successfully.

When people think of autopsies, they don’t usually consider how investigating someone’s death may save or prolong the lives of others. Had this man’s death simply been taken at face value– an accident not worth exploring– this information may not have come to light.

Autopsy photographs showing defense wounds on the hands of Travis Alexander, who was brutally murdered in his Arizona home in June 2008.

The presence of multiple cuts on the hands and forearms of a murder victim indicates they attempted to ward off an attack with a knife, or a similiar sharp instrument. When a victim tries to wrestle the weapon off the attacker their thumbs and fingers can suffer deep slashes and lacerations. Livid bruising on Travis Alexander’s knuckles suggests he fought heroically for his life before being stabbed repeatedly and shot. His ex-girlfriend, Jodi Arias, was charged and convicted of his murder.

Stages of Decomposition

1. Fresh: chemical breakdown of the body but not visually apparent. Algor, rigor and livor mortis starts to happen but no decomposition odours

2. Bloat: gasses accumulate in the body from anaerobic activity in the abdomen and odours begin. This stage ends when the body deflates.  

3. Active decay: body is wet from the decomposition fluids and strong odours begin. Flesh begins to disappear.

4. Advanced decay: Flesh is mostly gone and body begins to dry

5. Dry remains: No odour and bones are exposed to the elements (animals, environment)