Serial killers do not think the same as a gang member does. Gang members first of all are businessmen and they kill because of business related expenses and to keep anothers from testifying in court. Murder, to the gang members are simply the cost of doing business and nothing more.
Serial killers kill because they get sick pleasure from killing and money has nothing to do with a serial killer. For example even if you gave a serial killer $100,000 This is for example only, the serial killer won't care about the money and if anything it will probably go to food, the bills and not on expensive things like a fancy car, nice house things like that. Gang members want expensive things but a serial killer will kill just simply because of the sick pleasure they get from killing.
You are right, Not all white males are serial killers and there are many anothers who are serial killers of all races. I have met some people who in my guts I could sense they were serial killers but there was no proof and I stay away from them because their minds are not working right and you can sense the evil coming from them sometimes you catch a glimpse into their souls and you know it is not good at all. I would not be surprised if my sense and premontion about some of those guys I came across or met before do turn up on the nightly tv news and the police are looking for the serial killer. It don't surprise me because I have met some real nutcases in my time.