Killing
If you dream about killing a person, an animal or see people or animals being killed, this does not mean you have latent violent tendencies. Instead it can mean the death of thoughts and actions that have been restricting your personal growth. A deliberate act of murder might suggest hostility, with the identity of the victim and murderer assisting with the interpretation. Killing an authority figure typically suggests a desire to escape social or personal constraints. Killing a parent points to unresolved childhood conflicts, perhaps deep-seated resentments that have not been expressed. If the parent was of the opposite sex, Freudians might consider it as evidence of the Oedipus complex. A dream of poison - either poisoning someone or being poisoned yourself - may refer to some underhand action we are taking or which is being taken against us. Look for clues in the dream. Who or what is being poisoned? Is someone you know in waking life poisoning your attitude unbeknownst to you? What is the color of the poison? Are you poisoning yourself in some way?
Violent Death
If you watch a murder, this refers to aspects of yourself that have been denied expression. If you are running from a murder in your dream, it depicts something you feel threatened by in waking life. If you are the murderer, this may express intense emotional hurt towards someone, typically parents; the murder itself will be a symbol of the killing of the emotional bond or a warning that you are are on an emotional 'knife's edge'. Dreams in which you kill someone may also point towards an internal conflict, especially if you harbor no ill will towards your dream victim i real life, or indeed if they were a stranger or an animal. If someone provoked you into killing them in your dream, this may tell you what it is about yourself that you need to kill off. Animals symbolize aspects of your instinctual nature in dreams, so if you killed a cat, dog or any other animal in your a dream, ask yourself what that animal represents within you. If someone is trying to kill you in your dream, your unconscious may be alerting you not to a physical threat but to a real emotional or professional threat that someone poses to you. If you were unable to identify the dream killer, your unconscious may have been suggesting to you that you are being victimized in waking life by a person, a group or organization.
Dreams in which you are choking or strangled suggest conflict or indecision, as when you choke on words. They can also suggest repressed emotions, or emotions or memories struggling to be recognized. Because it is associated with the element of water, drowning indicates a sense of being overwhelmed by difficult emotions or problems. If the symbol of the guillotine appears ion your dream, you may be afraid of losing self-control or of losing contact with a part of yourself or someone you value. The guillotine also represents severance of some kind, so what is it that you need to cut out of your life? If someone is poisoned in your dream, this refers to attitudes, thoughts and behavior patterns that are not good for you. If you commit suicide in dreams; it may depict a sense of hopelessness; perhaps you have been working too hard lately and haven't been taking care of your health. Or do you feel a desire to retreat from life's problems or suffer from feelings of failure? It may also be a sign of represses anger concerning relationships or business. If someone else is committing suicide in your dream, this could be a sign that you want them out of your life.
~from The Element Encyclopedia of 20,000 Dreams by Theresa Cheung