This is an attempt to classify homicides into different categories. Elements of section 5, mental illness, may contribute to the other categories.
1. Fights and disputes
A common type of homicide. An argument or dispute breaks out, leading to fighting. If weapons are to hand homicide becomes a real possibility. There is no rational motive – such as financial gain. There will likely be elements of self defense ( “he picked up a knife so I shot him” or “I thought he had a gun so I shot him”).
1.1. Fights between intimate partners, or ex-partners.
Common is for abusive, violent boyfriends to kill their partners, after being rejected, when the girlfriend is leaving.
Sometimes one partner kills the other for financial gain, typically during a divorce.
Sometimes women kill their partner in self defense.
Occasionally abusive, violent women kill their partners.
1.2. Other fights and disputes
Often alcohol or drug related, or disputes over property, noise, annoyance. Usually not premeditated.
Revenge killings. Honor kilings.
2. Homicide related to burglary, robbery, drug crime
During home invasions, robbery of stores or other properties.
Elimination or witnesses, homicide while evading capture following a robbery or other crime.
3. Other homicides for financial ( or similar gain )
Neglect or murder of step-children
4. Homicides for a political motive
Terrorism, political extremism.
5. Homicides due to mental illness / mental incapacity ( taken broadly )
Paranoia ( schiophrenia, or due to PTSD )
Depression ( murder-suicide, infanticide )
Extreme child neglect / bad parenting.
To be continued, first draft.