Unfortunately a lot of these bastards aren't able to cease and desist. Probably the best way to describe it is an uncontrollable addiction where the activity progressively escalates as the time extends. Like a serial killer, each time the next one is fewer days till they have to go do it again. Next time shorter yet.
Classes with FBI profilers and prison psychologists and former dectec. team heads from the big city's, had basically the same analysis and outcome.
These guys have no social values nor do they understand what they are. They'll pass a polygraph test with no problem.
There are similarities amongst them but they're all different at the same time. A lot of them put a sexual connotation to it and are unable to get off otherwise.
Most of the time the manner of killing is up close and personal, knife, choking, beating, rather than a gun because a gun is too removed and too quick and doesn't give them the stimulation they need. Water is often involved because it provides reinforcement to them and ups their state of excitement with visual, blood or splashing, audible screams, splashing, gurgling, and tactile where the guy gets wet, splashed, or covered with blood and/or water.
Taste would be mostly blood being cast about from the victim thrashing.
Symbolism can be involved with what's done to the victim, whether dead or alive, sexual aberration from severing or mutilating various parts of the body, phallic with broom sticks, ball bats, and the like.
Eventually they'll all leave some sort of trademark and eventually they'll all be caught,
only problem being how many they kill in the interim.
There is no cure short of helping them expedite their tour of hell.