Murder: Locating The Smallest Of Clues


Sure, anybody can pick up a bullet casing and toss it into a plastic bag. But what about the tricky, hard to find evidence? What do the pros use to collect that stuff?

Self-saturating foam swabs are ideal for the collection of trace DNA, such as shed skin cells. The investigator breaks the isopropanol-filled handle by giving it a squeeze, which causes the foam tip to become saturated with the 91% isopropanol solution. The foam tip is then wiped across the target surface to collect the DNA evidence.

Cuticle sticks for retrieving evidence from the cuticles and other hard-to-reach places.

Swab Shields provide a physical barrier that protects against evidence contamination, mixing with other samples, and they prevent transferring your sample to another surface.

Trace evidence tape is a great tool for locating and picking up items such as, hair, glass particles, and fibers. Simply touch the “sticky side” of the tape to a surface and then lift. Any item on that surface will cling to the tape. To remove the item/evidence place the tape in water (the adhesive is water soluble), then pour the water through a filter. Your evidence can then be retrieved from the filter.

Tacky MatTM is used to collect trace evidence from the bottom of shoes. Have your suspect step on one and you’ve just collected samples from places he’s walked. The Mat can also be placed at the entrance of a crime scene to remove items from the bottoms of officer’s shoes to prevent contaminating the scene with foreign material.

Hand sifters are used to screen out dirt and debris, leaving behind bone fragments and/or other small evidence (shirt buttons, teeth, etc.).


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Murder solved by a mushroom

Toss out the confessions, fingerprints, tire tracks, and DNA. After all, who needs them when you have perfectly good fungi just waiting to join you on the witness stand. That’s right, mushrooms and other fungi have taken their place in the world of crime-solving. In fact, investigators can use macroscopic and microscopic fungi to help determine time of death (TOD), the time since a body was placed in a particular location, and if the body has been moved since death.

In 2002, the bodies of two young girls, Holly Wells and Jessica Chapman, were found lying in the woods near Lakenheath, Suffolk (UK). Without a clue to go on police called in forensic botanist Patricia Wiltshire, a former archaeologist, to see if she could “dig up” any evidence.

Patricia Wiltshire

Wiltshire agreed to help and traveled to the scene where she examined the foliage in the area where the girl’s bodies had been discovered. She noticed something a bit unusual with a group of stinging nettles growing in a ditch.

Stinging nettle plant

A closer look revealed the sprouting of new sideshoots on the nettles, something that only occurs when that particular plant has been damaged by trampling, or other such disturbances. Not only did Wiltshire’s find indicate that someone had walked there, the new shoots have a very specific growth rate—13 days at that particular stage. Therefore, Wiltshire was able to provide police with a time-line. The bodies of the girls had been dumped in the woods 13-and-a-half days earlier, which was when the girls were last seen.

When police finally located a suspect, Ian Huntley, Wiltshire was also able to positively match pollen found on his shoes and in his car to the type in the ditch where the bodies were found.

Connecting plant material and soil to the scene of the crime and to the murderer is nothing new. I once worked a murder in the 80’s where the only clues I had were two small pieces of dried, grayish mud found in the floorboard of a suspect’s car. Long story short, the mud matched the soil found only on a particular riverbank. The clumps of mud also contained a few seeds from plants also found only in that particular area. Guess what? Yep, the mud and seeds were from the area where the murder victim had been discovered.

Remember, fungi (trace evidence) grows just about anywhere, such as stone, leather goods, plastic, lumber and other wood, tile, brick, and concrete.  In fact, approximately 50-100 different species of fungi can be found in a single soil sample. So, the clues are there for the harvesting, and plenty of them. Someone just needs to do it. After all, a good investigator is a creative investigator.



If you watched this week’s episode of Castle then you witnessed Lanie Parish, V.D. (Voodoo Doctor) examine the body of a murder victim/floater and then say something like, “According to lividity, I’d say the time of death was 12 hours ago, at most.”

Well, we all know that lividity is not a good indicator of TOD, right? And when a person drowns, or is tossed in the water at the time of death, lividity can be absent, or even manufactured by swift currents. So Lanie’s writers were mistaken on all accounts.

So how do the experts determine how long a body has been in the water?

When a body is discovered on dry land there are many indicators of TOD, such as insect activity, body temperature, and rate of decomposition. But those indicators are either highly deceptive or nonexistent in “floater” cases. Therefore, if no one sees the body at the time it was dumped in the drink, there’s really no accurate way to know how long the victim had been under water.

Seeing the need for an accurate method of determining “time in the water,” scientists at the University of Otago in Dunedin, New Zealand began studying the various types of bacteria found at different stages of decomposition. They conducted the study at varying temperatures on submerged pig skulls (pigs decompose at a very similar rate to humans).

The team of scientists, led by forensic biologist Gemma Dickson, soon discovered specific bacterial signatures were found at each stage of decomposition. Therefore, the length of time in the water can be pinpointed by determining which bacteria are present upon discovery of the body. A remarkable discovery that, hopefully, can soon be used by law enforcement to determine time of entry into water.

Gemma Dickson University of Otago image

Medical examiners sometimes get a bum rap. Their life is not always about plucking the innards from every Tom, Dick, and Harry they meet. M.E.s and coroners play a huge role in solving homicides, and many times they alone do the crime-solving. They’re also responsible for protecting the most valuable piece of evidence in a murder case – the body. Here are a few items used in that process:

Tamper-proof body bag seal (What goes in a body bag, stays in a body bag).

Toe tag (Don’t want to mix up the bodies. Sometimes it’s quite crowded in those cold rooms).

Big Girtha (extra large) body bag w/10 handles and 2 zippers (For those victims who never made that call to Jenny Craig).

Tyvek boot covers – w/PVC bottoms for traction

Evidence drying cabinet

And for that someone special who has everything…

Dead Men Talk (on front) CSIs Listen (on back) T-shirt

Sally Slugger skeleton

Homer Runner skeleton

Crime scene bumper sticker



And for undercover work…

Crime scene boxer shorts

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.

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.


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.



Upper chest area of a murder victim.

Ligature mark on the neck from strangling.

Post autopsy “Y” incision sutures.

The end. Really…




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