Do you know the difference between misdemeanor involuntary manslaughter and first-degree murder? It is easy to think any killing of a human being is automatically a murder, but in reality, the killing of a human being is called a homicide. It is up to the police and county attorney's office to determine whether it was a murder. Even before a death is considered a homicide, if the circumstances are right a death investigation is started. In those cases, the body is sent to the state medical examiner's office and officers get to work gathering evidence. A homicide is a manner of death. Other manners include suicide, natural and accidental. Manner of death is separate from cause of death, which is the specific physiological reason the person died. What caused that death is up to the prosecution to prove.