First, let's look at the definitions involved:

• Murder: When someone knowingly causes the death, or injuries resulting in death, of another person.
  
  
• Manslaughter: When someone causes the death of another through extreme indifference to human life.
  
  
• Self-Defense: When someone causes the death of another in order to protect himself or his family.
  
  
• Suicide: The deliberate taking of one's own life.

These definitions are pretty consistent, but with the right information, the boundaries can be blurred, either accidentally or by design. For instance, murders can be made to resemble suicides, or manslaughter can become murder if sufficient motive and premeditation can be proved. If your antagonist is cunning enough, a suicide could be staged to look like a murder.

This article will give you some basic information, such as types of weapons used and what the choice of weapon says about a person, helping you set up an effective and believable murder for your protagonist to solve.

Firearms

The first and most often used weapons are firearms. Firearms, which include a wide range of handguns and rifles, account for three out of every five murders committed in America. Most handguns are fast and easy to use and require little, if any, training. With a gun, it doesn't matter how big or physically able you are; anyone from a small child to an elderly person can pull a trigger. Women rarely commit murder, but when they do, a gun is most often the weapon they chose because it eliminates the physical differences between the sexes, allowing a 100-pound woman to kill a 300-pound man, when any other weapon must be used at close range and could easily be taken from her.

When it comes to suicide, 64% of men and 40% of women make firearms their death of choice because it's quick and relatively painless.

Following are a few ways to tell murder from suicide.

• Where on the body the injury occurred: A shot to the side of the head, in the mouth, or to the front of the chest is usually suicide. Wounds located anywhere else are most likely homicide.
  
  
• Distance of gun from the body: Most suicide shots are at contact or near contact range, causing a burn mark around the wound and leaving gunpowder residue (which can be wiped off). At contact range, and if the gun is fired just above a bone, such as the skull or the sternum, a star-like wound is produced. Anything further away is likely homicide.
  
  
• Angle of the shot: Most suicide shots are angled slightly upward.
  
  
• Number of shots fired: After one shot, even if a suicide victim isn't dead, he would likely be unconscious or physically unable to fire a second time. Multiple shots usually indicate homicide.
  
  
• Presence of gunpowder residue on victims hand: If a man shot himself, there would be powder residue from unburned carbon on the hand that fired the gun.
  
  
• Shots through clothing: A suicide victim will rarely shoot through clothing. If he shoots himself in the chest, which is unusual, he will open his shirt to expose the skin. Shots through clothing suggest homicide.
  
  
• History, a note, other factors: If the victim left a suicide note, or was known to have personal problems, or if there was evidence of drug use or drinking, suicide is likely.
  
  
• Evidence of a struggle: If there are scratches, cuts, bruises, homicide is likely.

How fast a person dies depends significantly on where the wound is located and how quickly he can get help. A shot to the head might kill, or it might not. A shot to the abdomen might take hours to kill the victim, or he might bleed to death in half that time. A gunshot victim can be rushed to the hospital, have a bullet removed from his abdomen, be well on the road to recovery, then die a week later from some unforeseen infection. Anything can and does happen, which makes any scenario you come up with feasible for the needs of your story.

Knives

Knives are close-combat weapons. Unlike firearms, which allow you to murder at a distance, knives involve direct contact between the victim and the assailant. Because of this, a man usually stabs another man, or a woman. It's very rare for a woman to stab a man, even in crimes of passion, because it's much too easy for a larger, stronger male to overcome his smaller, weaker assailant. Most crimes of passion involve a man killing a woman with whatever weapon happens to be within reach, such as a kitchen knife, a fireplace poker, a heavy vase, or any number of other blunt objects. When a woman kills a man in a crime of passion, it's most often with a gun, his own if it's available. Women tend to see a kind of justice in killing a man with his own weapon.

As with gunshot wounds, there are several factors to be taken into consideration when determining if a death is homicide or suicide.

• Defensive cuts: In a homicide, there will be defensive cuts on the palms of the victim's hands and on the underside of her arms as she tries to fight off her attacker.
  
  
• Number of wounds and their location: A murder usually involves multiple stab wounds to the side, back or stomach. In a suicide, while there may be additional cuts across the wrist and tentative test stabbings to see if it will hurt, or to work up courage, there will usually only be one wound and most likely in the chest.
  
  
• Location of the murder weapon: In a suicide, the weapon will be at the scene with the victim's fingerprints on it. In a homicide, the weapon is often missing.
  
  
• Presence of a note: A suicide victim will almost always leave a note.
  
  
• Stabbing through clothing: A suicide victim will rarely stab herself through her clothing; instead, she will open her shirt to expose the skin. Stabbing through clothing, even if there's only one wound, may indicate homicide.

Hanging

While accidental hanging is rare, and homicidal hanging is even rarer, hanging is the third most common form of suicide and accounts for 16% of all male and 13% of all female suicides. Most people who commit suicide by hanging, jump from a chair or a ladder, choking to death slowly. Rarely is the neck broken. In order to break a neck, a drop of six feet or more is required, which rarely happens except in execution hanging.

Hanging, whether done with rope, an electrical cord or a belt, always leaves an inverted V bruise, and is easy to tell from ligature strangulation (murder), which leaves a straight-line bruise. Hanging compresses the veins, but arterial blood flow continues, causing small bleeding sites on the lips, inside the mouth and on the eyelids. As with ligature strangulation, the face and neck are congested with blood and become dark red.

Ligature strangulations are almost always homicide and the victims are almost always women. Often the murderer uses more force than necessary to kill the victim, causing deep bruises and abrasions around the neck. The victim will usually struggle, which results in damage to both the interior and exterior structures of the neck and throat.

Accidental strangulation is rare, but does happen, usually when a tie or a scarf gets caught in power machinery. Consider causing a murder that looks like an accident by catching a woman's scarf into machine gears. Or hanging a man by pushing him off a chair and making it look like suicide? The police would have a very tough time proving it wasn't.

Drowning

Drowning is a type of suffocation; the water prevents oxygen from getting to the brain. It's a slow, agonizing death with the victim struggling desperately to stay alive. Because of this, suicidal drowning is very uncommon. Once the lack of oxygen makes itself felt, the victim's survival instinct takes over until all he can think about is getting air into his lungs. All thoughts of suicide are abandoned in the face of actual death.

Most deaths by drowning are accidental and usually involve the abuse of alcohol or drugs. But one has to wonder how many of those 'accidents' are more than they appear? How many times has someone gotten away with murder because no proof could be found that a drowning was homicide? Maybe more than we think and here's why:

Homicidal drowning is almost impossible to prove by an autopsy. Drowning is a diagnosis of exclusion. In order to prove murder or suicide, surrounding facts have to be taken into account, such as other wounds, signs of struggle (overturned furniture, etc), or the presence of a suicide note. Most of the time, that's all the proof the police have. If a person is drowned, say in a bathtub, then thrown into the pool to make it look like an accident, even forensic science won't be able to prove it. They can only speculate about how the death occurred.

One of the problems of diagnosis is, that unlike drowning in a river or the ocean where samples of the water in the lungs can be tested for salt or other contaminates to determine where the drowning took place, the same cannot be done with the water in a pool. Chlorine dissipates from the lungs almost instantly. By the time an autopsy takes place, there's no trace left. If a murderer were to hold a person's head underwater in a pool, the police would have no way to prove it was homicide, in fact, most drownings are ruled accidental for just that reason.

There are a few factors that could suggest whether a drowning is homicide, suicide or accidental, but with the proper set up, you can make a fictional drowning look like anything you want.

• Shallow water: Drowning in shallow water could indicate either an accident or murder, especially if the victim is undressed. A killer will remove the victim's clothing to make it look like an accident. If the body is fully clothed, it is most likely a suicide since the victim doesn't want to be found nude.
  
  
• Suicide Note: The presence of one usually indicates a suicide, but could be faked.
  
  
• Evidence of other injuries: If the victim shows evidence of gunshot wounds, bruises or cuts, it's likely murder. The discovery of alcohol or drugs at the scene could indicate an accidental drowning.

Drowning is a form of murder that you, as a writer, can use to good effect. Why not stage a murder and make it look like an accident, or use an accidental drowning to frame an enemy for murder. Your protagonist would have a hard time solving the case either way.

Poison

Poison, especially an overdose of pills, is the second most popular form of suicide, at least with women, accounting for 38% of all female and 15% of all male suicides. The reason is easy to understand. With the right kind of poison, it's a relatively painless death, no muss, no fuss, no blood to mess up the bedding. And if someone doesn't really intend to die, a pill overdose gives her the highest chance for survival if she's found and taken to the hospital in time to have her stomach pumped.

Poisoning is a very popular form of murder, especially in literature. It can easily be slipped into a victim's food or drink and depending on the intended outcome, can either act slowly, over a long period of time, or rapidly, within minutes or hours. Certain poisons can imitate diseases, causing the doctor to misdiagnose a medical problem, or can cause a steady weakening of the body, making it susceptible to other, more serious diseases.

Poisons can be found anywhere, in virtually anything, from plants to animals to the pain killer you take for your headache. Anything, in a high enough dose, can be fatal. And if your victim has other problems, such as heart disease, the right kind of poison can look like a heart attack. Unless the doctor has suspicions and orders an autopsy with a drug screen, it's very likely your murderer will never be caught. With the right poison, and the knowledge of how it affects the body, you can stage any type of murder your plot calls for. Poisonous plants made into lethal salads, deadly insects imported and tucked into the victims bedding, the wrong kind of mushroom cooked into an appetizing dish, or street drugs slipped into a person's drink. The choices are numerous.

Committing murder -- in literature that is -- can be fun as you cause your detective innumerable headaches trying to solve the difficult crimes you've set him. Sprinkle your plot with plenty of bodies and readers will clamor for more.