Hey, thanks for the correction! Wiki link.
Ridgeway had a 19 month killing spree in the early 1980s (starting Summer 1982?): DNA evidence caught up with him in 2001. He had given a saliva sample in 1987. He was IDd as a suspect in 1983-1984. He apparently killed one person as late as 2000, if I understand the wiki link correctly.
I’m wondering whether the police pressure hypothesis applies here. I have not seen a definitive timeline though.
Maastricht’s Crime Library link states, “In a study of 300 serial killers, it was found that 2.3% had turned themselves in, one way or another.” This study is not cited explicitly, but appears to have been conducted by the author. From the bibliography:
Ramsland, Katherine, and Karen Pepper. “Stopping a Serial Killer: A Study of 300 Cases,” Unpublished manuscript, 2006.
I’m not sure what “in one way or another” may mean.
From what I’ve read about serial killers, I’d assume that this is referring to the ones who write letters to the police that include evidence that leads to their arrests, or the ones who leave messages at crime scenes, demanding to be caught. They don’t actively turn themselves in, but rather invite the police to catch them. and seem ultimately relieved when caught.
I’m not sure which article it was on Crime Library, but I’d been reading it not too long ago and it made reference to one man who scrawled on a mirror in lipstick a demand that the police please stop him. He didn’t really turn himself in, but he was happy enough to be stopped and had left a clear trail. I’ll have to poke around the site to see if I can find who that was and further details on it. I’m assuming that incidents like that are the “or another” aspect of turning themselves in.
That was William Heirens.
Thank you! Yes it was. Well, unless you ask him, in which case it isn’t, since he apparently changed his story later on.
I would add the product tampering case from back in the early eighties to the unsolved serial killer list. Seven people in the Chicago area were poisoned with cyanide added to Tylenol capsules on store shelves. No one was ever arrested for those crimes, although someone was arrested for an extortion attempt after the fact and a couple of copycat murderers were caught. I sometimes wonder about whether the guy who did it got 25 years for an unrelated crime and is just getting out now.
Following Bill Door’s comment, a serious treatment of this question would involve a breakdown of different types of mass murderers. For example there are hit men, psychos, politicos such as the Unabomber and other terrorists and …well I’m not sure how to classify the Tylenol killer.
Presumably different motivations might correspond to different reasons to cease their criminal activities.
The movie strongly suggests the killer was Arthur Leigh Allen, and I was going with that assumption when I mentioned prison time.
Even if Allen wasn’t the killer, it still appears that Zodiak struck several times and then quit.
According to the SF Chronicle (found via Wikipedia) DNA evidence appears to have cleared Arthur Leigh Allen, who died in 1992.
Interview. No mention of any “project.”
About BTK’s last project: I’m going from my memory of articles published at the time in The Wichita Eagle. Rader was said to have told police he was working on another project. Indeed, he reportedly claimed that after he left one of his “communications” to police to be found, he headed for a would-be victim’s home; but no one was home.
Measure for Measure: While I’m in no position to rule it out, I’ve read nothing to indicate that Park City Compliance Officer is an elective position, and would be quite surprised if it were. (Forgive me a mild snark, but writing citations is a far cry from murder!)
I suspect that this is a whole different pathology than the typical violent serial killer. It may have been an attack on Tylenol, and the victims just a means to that end.
It’s probably a coding error in the loop that sets the next serial number after each killing. I’d look for an unhandled condition in the IF clauses, maybe they forgot to code for a default choice of victims if none of the other parameters seemed to apply?
Sorry, no cite, but I recall it was done by a man to kill his wife, and simply tampered with other random packages to take the heat off himself. Although I could be completely wrong.
Hypothetically, at the far end of the scale, they might be forced to stop if they kill everybody and have no more victims. 
I saw rader on TV-the interview was chilling. It made me realize that Rader (the “BTK” killer) wasn’t really a human being-he is missing something. i recall he was actually pleased to recound his activities in court-in his words “I felt pretty good about what i did”.
The “man”? lacks any sort of compassion or humanity. I doubt he knows any better-the quicker he is disposed of, the better.
Well, not completely wrong. Around 10 years after the original Tylenol case someone poisoned his wife using cyanide in Sudafed. He also poisoned some other packages and placed them on store shelves to attempt to divert blame. There was also a woman who tried to poison her husband with Excedrin that had been tampered with. The original case has never been solved, although someone did end up going to jail for an extortion attempt, it was never proven that he had anything to do with the poisonings.
Profiler claims that serial killers never stop was based upon old data from a very limited data group: specifically those killers who were caught decades back before DNA tests and so forth could catch killers who hadn’t been active for a long time.
In other words, the idea was that because all the serial killers we knew about then hadn’t stopped until they were caught they assumed none of the others did too. They didn’t even stop to think that the sample set they had by its very nature would only be those ones who were so reckless that they got themselves caught fairly easily. It’s a classic logical fallacy, and one that has been demonstrated incorrect in a number of newer cases.
Wikipedia, via Answers.com, says, “In 1991 Rader ran and was elected as a Republican[2] supervisor of the Compliance Department at Park City…”, FWIW. Answers - The Most Trusted Place for Answering Life's Questions
Essentially, he was allegedly elected as dog-catcher.
The footnote links to CNN, which does not mention the election though. My googling has turned up nothing. Pending substantiation from another source, I retract this claim. Ark Valley News appears to indicate that he was appointed:
I don’t suppose you know who did the Wiki article (I did a too-brief scan for a name and saw nothing). This seems to be a great example of how the closer a source is to facts, the more accurate it is.
(I’m in the unexpected position of being able to vouch for the ability of the Ark Valley News publisher, Les Anderson. He has taught journalism at Wichita State for many years, and I took a newspaper editing course from him in '83 or thereabouts. Not three weeks into the class he decided I had what it takes to be a copy editor [meaning, I guess, that I’m a hard-assed nitpicker]. Sometimes I wish I had listened to him. . . .)