Death Investigation

INVESTIGATION OF THE VIOLENT CRIME EXEMPLAR
"To be idle is a short road to death" (Buddha)

Any investigation into the world of violent crime, such as homicide, suicide, and sex offenses, carries with it some standard procedures of analysis and reconstruction which we'll discuss here in the context of fairly typical and uncomplicated (exemplar or unequivocal) crime scenes. There are a few similarities as well as differences with the crime of arson (sometimes treated a violent crime), but the homicide exemplar is so typical of the investigative process as a whole that it's often the only corpus delecti a student needs to know in learning how to investigate (Axelrod & Antinozzi 2003). Many of the skills involved in conducting a homicide investigation carry over into other crimes, not all, but many. Homicide is therefore considered an exemplar, or good example, to use in the teaching of criminal investigation. Homicide involves both the study of victimology and suspectology.

A few caveats are in order before we begin. One such caveat has to do with the necessity of speed or haste. A homicide needs to be investigated quickly because information and evidence will often lose its freshness and become tainted in short order. Another caveat is that just because you find a body at the crime scene doesn't mean you should launch a homicide investigation. Homicide is only the sixth leading cause of death in America. The following table illustrates the odds for average Americans:

Cause of Death	Odds of Occurrence
Disease Heart Attack Cancer Automobile Accident Suicide Homicide	1 in 1.3 1 in 3 1 in 5 1 in 42 1 in 81 1 in 84

There are times when a preliminary walk-through will tell you that the death is by natural or accidental causes (the top four causes of death), but as a general rule, you should treat all apparent suicides as homicides at first. With suicides, you may or may not find a note left behind for loved ones, but if you do, you should treat it as a questioned document. A suicide can, of course, also be accidental or intentional. The most common accidental ones involve misuse of firearms and drugs. The most common intentional ones involve hanging and jumping (although sexual asphyxiation is usually classified as accidental). The special case of drowning is equally likely to be either accidental or intentional. The following table lists the most frequent order of occurrence for intentional suicides along with a rank order of the most damaging life stressors:

Intentional Suicides	Most Serious Stressors
1. Hanging 2. Jumping 3. Carbon monoxide 4. Poisons 5. Slashing wrists 6. Firearms 7. Drug overdose 8. Drowning	1. Death of spouse 2. Divorce 3. Marital difficulties 4. Trouble with the law 5. Death of friend or family 6. Serious illness or disease 7. Fired at work 8. Retirement

With homicides, a good rule to follow is make the arrest within 72 hours or the chances of ever making it plummet (Morn 2000). Another caveat is that it is not absolutely necessary to have a body to launch a homicide investigation. Missing persons situations are somewhat special, and you should refer to your department's policies on that, but in most cases when you suspect a homicide, it probably is a homicide, and when you suspect an abduction, it probably is an abduction. If you can't find the body, it's most likely buried or underwater somewhere, unless you're dealing with kidnapping, serial killing, or sexual cannibalism (O'Connor 2001). Remember that insects and animals will eat up about 60% of the corpse within a week, and unless they are weighted down or stuck on an underwater eddy obstruction, sunken bodies usually become "floaters" by the end of a week.

Our society does a pretty good job of tracking dead people and determining criminal causes of death. There's only about 25,000 homicides a year, and you can probably have some confidence in that number as an accurate figure representing the real number of homicides every year. Homicide is a crime with a pretty high clearance rate; at least 65% of all homicides are solved by arrest of the perpetrator, and some years, the percentage is closer to 85%. Guns, alcohol, drugs, love, felony-murder, blunt force trauma, knife fights, and strangulation are all associated with homicide. The LAW of homicide needs to be clearly understood:

Treat all cases of death that you come across as a homicide at first, even suicides. Remember that motive, circumstance, and purpose are key elements in determining exactly what type of homicide you're investigating. Be prepared for self-defense and insanity claims. Look at the crime scene for evidence of passion, provocation, and signs of struggle. Analyze the wound patterns, and try to reconstruct what happened from the fingerprints, bloodstains, and ballistics.

It's important to appreciate how death comes to the attention of police, and more importantly, how the case happens to come across your desk. Chances are that someone you know or something you already know about is related to the case, so there's going to be a linkage between this case and one or more of your other cases or something in the police files, like repeated calls for service to an address for domestic problems. You definitely want to know who called the police and exactly when they called and what their voice sounded like over the telephone. A linguistic analysis might be helpful. You might also want to think about initially consulting with others in your department about what they suspect, but it's best to keep an open mind.

If you are the first responder (not likely), then exercise procedures called for in the acronym ADAPT (Assess scene, Detain witnesses, Arrest perpetrator, Protect scene, and Take notes). If the victim is still dying, then take their dying declaration. This is compelling courtroom evidence. To be admissible, the victim must believe their death is imminent, and what they say must specifically concern the cause or circumstances they believe about their impending death. If the victim is apparently dead, determine if they are really dead and/or attempt resuscitation. Here's the legal signs of death:

If the dead person is missing, ask any witnesses if they know where the body might be. If paramedics, the coroner's office, or Medical Examiner took it, remember that they "own" the body, but you control the crime scene. Use witness accounts to put chalk lines down where the body was. Start note taking on characteristics having to do with BODY location, then turn to likely entry and exit points. Secure the scene after that, and then record your own movements. If night is falling, and the scene is dark, call the fire department because they usually have excellent lighting equipment.

The body of a dead person is like a encyclopedia of information and knowledge, if only you know how to read it. The thing to remember is always corroborate, and double-check your identification sources. Don't assume the ID in the victim's wallet isn't a planted ID. Assume that everyone at the crime scene is going to lie to you. There will be the usual cast of characters, and some of them will be serious jokers while other are joking seriously. Confiscate all personal effects of the victim. Look at the victim's clothing and body for stains, laundry marks, monograms, tattoos, etc. Be mindful of planted evidence. Take pictures (facial shots, if not too graphic) and get a family member or somebody to ID the person (if not too graphic). Order fingerprinting, DNA tests, dental X-rays, forensic anthropology on the bones, or whatever you need to do in identifying the body. As a last resort, release a composite sketch to the media "Do You Know This Person?"

There's always going to be at least two (2) estimates of the time of death -- the police department's official estimate (which may or may not be yours) and the Medical Examiner's estimate. Legally, you should be within 4 hours of being accurate, but this is a tough standard even for the best coroners. Remember that, after death, the body starts to cool down to whatever the outside (or room) temperature is. At death, the body starts to drop from it's normal 98.6 degrees by a factor of 3 degrees the first hour and a factor of 1 degree each subsequent hour. Then, after 30 hours, it starts to go up again because of the heat generated by decomposition (but this varies by room or outside temperature, so you need to know weather conditions). The following table illustrates:

Rigor mortis is also something you should know about. The body is limp until about 5-6 hours after death, then a hardness begins to set in around the jaw area in front of the ear (temporal mandibular joint area). It then spreads throughout the body for a period of time, and then the body goes limp again. The following chart illustrates:

Lividity is the effect of gravity on blood. You'll note that after death, all the loose blood in the body runs down to the lowest point of gravity. If the dead person is on their back, you'll notice these blueish-purple stains on their back. Lividity begins after only 3 hours, and the blood becomes dried after only 12 hours, so lividity is something to look for quick. It tells you if the body has been moved or transported when there are lividity marks in unusual places instead of the lowest point of gravity where you find the body. You can distinguish lividity from a bruise by pressing down on the skin area. Since with lividity, the blood is still in the blood vessels, when you press down on the skin, the skin changes color and turns white (or whatever skin color the person normally has). Bruises, by definition, are broken blood vessels, so when you press down on the skin area for them, you won't notice any color change; the skin area will just turn another shade of blueish-green.

The eyes dilate 7 hours after death (dilation is enlargement of the black pupil area). Drugs will also create unusual eye dilations, as will certain poisons, although breath odor is the more likely place to look for poison. After 12 hours, the whole eye gets cloudy and fish-like. If the person is disemboweled or has thrown up, look at the stomach contents. Anything eaten in the last 2 hours is undigested; food spends 6 hours in the small intestine and 12 hours in the large intestine. If your victim has been underwater, the average dead person sinks for about 8-10 days (depending on body weight), then they become "floaters" on about the 11th day (although a light person might float after only 7 days).

Decomposition begins in 30 hours and then starts to rise rapidly after 48 hours. The soapy, mushy remains of a body indicate they've been dead for 3 months. If they are partially mummified, they've been dead for a year. Decomposition is unmistakable by it's smell (the smell of death). You'll be able to see the gases coming out of small gas blisters all over the body, and you won't be able to overlook that bloated greenish tint that the whole body has. If it's an outdoor crime scene, chances are that small animals have eaten or carried off parts of the body, and even with indoor crime scenes, you're going to have the problem of insects (it wouldn't hurt to know some entomology). North America is home to a particular species (Calliphoridae) of fly known as the blow fly, and they love to lay their eggs on the bodies of dead humans. You'll probably discover bodies teeming with maggots (fly larvae). If you can locate the largest (oldest maggot), measure it in millimeters and add the number two (2), you'll have the approximate number of days since death. A comprehensive checklist of things for determining the time of death would include the following:

1. the temperature of the body and the rate of cooling
2. the degree of postmortem lividity (hypostasis)
3. the degree of rigor mortis
4. putrefaction
5. insect activity
6. analyzing stomach contents

Look at the body, how it's posed. Look at the wounds. Look for defensive marks on the knuckles or pieces of skin under the fingernails, anything that might indicate a struggle ensued. Examine the skins surfaces for wounds, pinpricks, needle marks. Look to see if anything's in the mouth, vagina, or rectal areas. If your victim's been raped, do a pubic hair combing. Bag & tag any traces of fluids. If your victim's been strangled, determine if there are any ligature marks. Strangulation marks are horizontal around the neck, and hanging marks are on an upward angle to the back of the head. Determine any poisoning or drugs from odors, color of lips, toes and fingernails.

The facial expression may tell you something or it may not (most of the time not, as upon death, the facial muscles relax and it is virtually impossible to determine what caused the death). Experienced investigators have marveled over the peaceful countenance of victims who have undergone horribly painful deaths. Nevertheless, there are some possibilities that you can go by as long as you realize we're treading more on myth than science here. Death by firearms may result in a shocked look of expression on the face. After all, that's what you die from in a gunshot injury: shock, either that, or they hit a vital organ. A strangulation death may have a gasping for air look. A blunt force trauma death may have a more painful than peaceful look. A knife or bleeding death may involve a fairly relaxed look. A drug overdose may be likely to involve a smile on the face, and some types of poisonings (strychnine) produce such violent convulsions that the back arches and this causes the facial muscles to contort into a sardonic grin. In reality, however, it is unlikely that you will be able to make estimates from facial expression, since this is not a sound method of investigation. When death occurs, the muscles relax, and are especially more relaxed by the time you look at the body in the morgue.

If you know bloodstains or ballistics, conduct an analysis of angle and points of trajectory. Look around for the murder weapon. It might be down the point of exit. The coroner's report may or may not be of any use to you. Often, they are full of medical jargon about the mechanism, not the cause, of death.

Next, you need to find out everything you can about your victim's background, especially their last activities in the previous 24 hours. This is called Applied Victimology, and it's your primary means of determining suspects. Examine telephone records, mail, email, food in refrigerator, business appointments, work and entertainment habits. Discretely inquire into romantic affairs.

Look into what enemies the victim had (business-financial; political; religious; love life; entertainment world). Find out if your victim has a prior criminal record. Obtain a list of previously known addresses. If you can, find out about your victim's medical and mental history. You will need to assess whether this is the kind of victim that could engage in provocation or not, just as you've already established whether or not the victim put up a struggle.

Canvass the area and interview all cooperative, suspicious-looking, and even random, disinterested bystanders. Don't make any "off the record" comments to reporters, and certainly don't tell anybody anything about any evidence you may or may not have found. Use your interview and interrogation skills. Get specifics about time and place from people so you can compare these specifics with the story they tell you later.

At this stage, you're developing a viable theory about what happened. From your analysis of the crime scene and victim's background, you should be able to come up with at least 2-3 theories about what happened. Some standard motives are: anger, love, revenge, jealousy, and profit. More perplexing are hate crimes and senseless acts of violence. It may even be possible that you've got a serial killing on your hands.

Many investigators wait until they've gotten a feel for the geographical and cultural aspects of the area the victim (and possible suspects) are from before taking a stab at motive. This is the legwork of investigation; not so much putting people under surveillance, but checking out different parts of town, getting to know the habits and character of the people from that neighborhood, and linking this particular crime up with the patterns and motives from similar cases in similar neighborhoods. That, in short, is homicide investigation.

All victims of sexual assault, whether living or dead, should be examined in the same manner as for live victims of rape. The optimal procedure is to have a sexual assault examiner (SART or SANE teams) conduct their business in conjunction with any criminal investigation and/or autopsy. SART stands for Sexual Assault Response Teams (consisting of first responders, special investigators, and victim advocates), and SANE stands for Sexual Assault Nurse Examiner. According to Gonzalez v. State of Texas 1991, SANEs are allowed to testify as expert witnesses.

The physical evidence that is most useful in a sexual assault case involves DNA, fingerprints, semen, hairs, fibers, and blood. Other evidence may be useful (such as footwear impressions or fingernail scrapings), but these are the standard trace items focused on in every so-called "rape kit", and by the way, rape victims are not called "victims" but patients (the medical community prefers this term). The logical solution to a rape case involves matching trace evidence from three places: the crime scene, the victim, and the perpetrator. Alcohol and drugs are involved in about 33% and 25% of rape cases, respectively.

Most forcible rapists are stupid, predictable criminals. 99% of the time, they will attempt an alibi defense by claiming mistaken identity. They will frequently say the rapist must be someone who looks like them. Hence, the importance of physical evidence, like DNA, that individualizes the offender should be obvious. A voice lineup may also be useful. Once the evidence identifies them, they often change their story, and claim it was consensual sex after all. "Oh yeah, I guess I was dating that girl", they will say, and those fingerprints of theirs must have been from one of their many sexual liaisons. Depending upon how effective their lawyer is, courts normally have little tolerance for these kinds of games, but it's played 100,000 times a year, year in and year out in America, and police only have about a 50% clearance rate for rape. Sex crimes that do not qualify as rape are called sexual assaults and occur 430,000 times a year. Criminal investigators should therefore understand the importance of things like lie detectors and recorded or sworn statements or depositions in these kinds of investigations.

Another type of rapist is more insidious and uses newer drugs to erase the memories of victims (LeBeau & Mozayani 2001). The victim, out at a social event, meets and mingles with a respectable-looking person, who secretly slips gamma-hydroxybutyric (GHB), rohypnol, or ecstasy into the victim's drink. The victim, totally unaware, becomes incapacitated and is taken by the perpetrator to an apartment where she is raped, sodomized, and photographed while unconscious. She later awakes somewhere else unaware of what has happened, save for the bruises or lethargic aftermath of the drug. She may only realize 24 to 48 hours later that she has been sexually assaulted, too late for most examinations to be useful. GHB can be easily made in the kitchen from industrial solvents and paint remover, and recipes can be easily found on the Internet. Other rapists of this type use their own barbiturate or benzodiazepine prescriptions, and those employed in health care may use various hypnotics or sedatives they have access to. Investigation of drug-facilitated rape usually requires extensive medical and expert witness assistance.

Another type of insidious offender abuses or molests children. Victims and their families frequently report the offender was the nicest person you would ever want to meet. Although a mandated reporter system works well in detecting much child abuse, involving those who work in medicine, social services, psychology, child care, education, and law enforcement, some pedophiles and organized rings of pedophiles go to great lengths at planning and carrying out their crimes. They are increasingly using the Internet for solicitation and trafficking in child pornography. About 500 of these types are rounded up every year by the FBI and other law enforcement task forces via investigators posing as bait (e.g., children in chat rooms). The typical offender is an upper-middle-class, educated white male between the ages of 25 and 45. Most apprehended offenders will mount an entrapment defense, so it's important for investigators to document everything said or done very precisely.

Nothing is probably more important in a sex crime investigation than protecting the victim, which is an oft-misunderstood phrase that goes beyond interviewing the victim in private. It means respecting the victim, relating to the victim, building a rapport with the victim, and at least a dozen other things that males cannot ordinarily understand. For this reason, some police departments prefer or require that female officers be assigned to the investigation of such cases. While documentation of everything said is important with sex crimes, there has to be some flexibility and room for the victim to "vent", express their emotions, and bounce thoughts and feelings off a sympathetic listener all without worrying about someone recording everything to be used against them later. Victims of sex crimes often "act out" in strange ways afterwards, and sometimes they are the ones who need protection from themselves. Subsequent contact between the victim and any potential suspects must be avoided at all costs.

A sex crime investigation requires continual, ongoing two-way communication between the police investigator and crime lab personnel. Most crime lab directors know this, and have set up procedures for it. The problem is that all the different pieces of trace evidence are going to need background control samples, not so much from the time the crime was committed, but from the need to include and exclude all the possible suspects that each laboratory test reveals. Many instruments used in the kinds of lab tests required are destructive of the evidence, and more evidence needs to be continually available. Investigators need to be prepared for when a lab analyst calls and says they need more evidence. You should also be aware that potential suspects in sex crime cases frequently sue police departments for sloppy investigative work by not taking background samples (shoeprints, vacuuming fibers, etc.) from their apartments.

The sex crime investigator is going to need special equipment or special expertise. Extracting fingerprints, debris, or DNA from duct tape or other binding material like rope knots is extraordinarily difficult to say the least. Obtaining semen evidence, for instance, requires the use of forensic light sources. Semen has a faint fluorescence under a Wood's lamp (long-wave ultraviolet light), and many fibers have a strong fluorescence under this kind of light. Both the victim's body and their clothing should be subjected to forensic light analysis. The victim's clothing not only tells if a struggle ensued (torn or buttons missing), but clothing worn after the assault may reveal evidence (from anal or vaginal discharge). Don't rely exclusively on semen evidence, as more and more rapists are starting to use condoms.

Long-term follow-up on the victim is important for photography purposes. As with domestic violence, some bruises don't show up until long after the assault. Bruises are bluish-red after a few hours, purple within a few days, green-yellow at the end of a week, and brown after a week. Most bruises take 2-4 weeks to disappear. Documentation of internal damage to the vagina and rectum is going to require the services of a forensic gynecologist (if you can find one) or a medical professional. They can usually conduct what is called a colposcopic examination (which produces photographs) and detect abrasions, fissures, transections, synechiae, petechiae, and edemas which may indicate microscopic evidence of a rape. Not too much should be made of these photographic blowups, however, since courts frequently exclude them for being too gruesome, prejudicial, or subject to expert disagreement.

When developing your theory or theories about what happened, it's important in violent crime investigation to give equal consideration to motive, means, and opportunity. A lot of the literature on serial killers and repeat offenders is too heavily slanted toward motive and motive-based typologies. Equally, if not more important, is means (who had the physical strength to commit this particular crime) and opportunity (who had access to or could have been present at the crime scene). It's helpful to create what is known as a time line, which accounts for the whereabouts of all the principals in the case before, during, and after the crime. Suspects can be systematically eliminated one-by-one on the basis of opportunity alone. You can always go back and consider motive and means later. Criminal personality profiling should be reserved for when there is no apparent motive.

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Last updated: Mar 6, 2008
Not an official webpage of APSU, copyright restrictions apply, see Megalinks in Criminal Justice
O'Connor, T. (Date of Last Update at bottom of page). In Part of web cited (Windows name for file at top of browser), MegaLinks in Criminal Justice. Retrieved from http://www.apsu.edu/oconnort/rest of URL accessed on today's date.