Besides these four basic categories listed, there are also dozens of other subcategories that make serial killers unique based on their killing rituals and the nature of their crimes.For example, "black Widow" is the title given given to female serial killers, because it is known that a female black widow spider always kills and digests its mate after laying her eggs.Many of these killers also sexually abuse their victims, but they are not motivated by feelings of lust.
After that, they hide the victim's corpse and they move on to their next victim, that is, unless of course they are caught in the act of doing so. They always have a controlled crime scene, hence categorizing them as organized makes them much easier to track.
Mission-oriented serial killers are killers that feel that they are doing society a favor by ridding it of certain people; these can include young women, prostitutes, drug dealers, or homosexuals, people they feel that society could do without. However, since these killers always go after specific victims, this makes them much easier to track down.
And, depending on the nature of their crime, they are either categorized as Every detail of their crime is planned out well in advance, and the killer take every precaution to make sure they lerave no evidence behind to link them to a murder.
It is not uncommon for this type of psychopath to watch potential victims for days to find someone they consider a good target.
"Lust killers" are serial killers that harm their victims largely for sexual arousal, and there are killers that form clubs that kill for sacrifice and acceptance into the group; these are called "group killers", but are more commonly refered to as Serial killlers can also keep mementos of their victims once they are dead.