John Wayne Gacy, and The Zodiac Killer, are probably the most iconic serial killers of the 20th century.

John Wayne Gacy 和黃道十二宮殺手(The Zodiac Killer)，可能是 20 世紀最具標誌性的連環殺手。

But can you name a serial killer from the last 20 years?

但你能叫出這 20 年以來的連環殺手的名字嗎？

Unless you're a serial killing nerd, probably not.

應該叫不出來，除非你是專研連環殺手的怪咖。

The 70s, 80s and 90s were the heydays of American serial killing.

70 年代、80 年代和 90 年代是美國連環殺手的全盛時期。

Now, I'm using America as an example in this video, nearly every Western country follows a similar pattern, it's just that you guys have the biggest data set and if I may say so, a penchant for serial killing.

我在影片中用美國為例，幾乎所有的西方國家都遵循類似的模式，但你們(美國人)的數據最豐富，而且恕我直言，有連環殺人的嗜好。

America has 4% of the world's population and 67% of the world's serial killers.

美國人口占世界 4% 而連環殺手占世界的 67%。

Here's the yearly average for the number of operational serial killers in the US for each decade.

這裡是美國每一個年代每年平均的連環殺手數量。

It exploded in the 1970s, peaked in '87 and has been on a steady decline ever since.

它在 1970 年代暴增，1987 年達到巔峰，此後逐年穩定下降。

We rarely hear about modern-day serial killers.

我們很少聽人論及「現代連環殺手」。

Either there's just a lot less around, they don't get reported on, or we've gotten really good at catching them.

也許是數量少了很多、沒有被報導出來，或我們已經很擅長逮捕他們了。

Technology has made us traceable.

科技使人類足跡變得可追蹤。

You try secretly eating 17 people today without using a credit card, phone, or the internet.

你試試看在不使用信用卡、電話和網路的情況下，偷偷吃掉 17 個人。

All while avoiding CCTV. Jeffrey Dahmer had it easy.

同時得避開閉路電視(CCTV)。Jeffrey Dahmer 的日子太好過了。

The ability to map a suspect's movements over the course of an investigation has radically changed policing, as has DNA profiling.

在調查過程中追蹤嫌疑犯行蹤的能力和 DNA 鑑定技術，徹底改變了警察的辦案模式。

California had a spree of unsolved crimes between 1974 and 1986.

1974 年到 1986 年間，加州有大量未破案的案件。

The police were looking for the Visalia Ransacker, the East Area Rapist, the Diamond Knot Killer, and the original Night Stalker.

當時警方正在追查「維塞利亞劫掠者」、「東區強暴魔」、「鑽石結殺手」以及「原始暗夜尾隨者」。

But DNA breakthroughs in 2001 linked all 170 cases to the same man.

而 2001 年 DNA 鑑定技術的突破，將 170 個案件都指向同一名男子。

Now dubbed The Golden State Killer.

現在他被統稱為「金州殺手」。

DNA allows police to connect unsolved crimes. Let's say they're investigating 5 murders.

DNA 鑑定技術讓警方能夠串聯未偵破的案件。假設他們正在調查 5 起謀殺案件。

This is their search area. But if all the crime scenes are found to contain the same DNA...

這是他們的搜索區域。但如果在犯罪現場都發現了同樣的DNA......

The killer is now likely to live somewhere in this smaller area.

那麼兇手可能就在這個較小的區域內。

With a decent chance of them being fairly central.

而且很有可能就在這個區域的中心點。

Connecting the crimes helps catch the murderer sooner, saving lives.

串聯犯罪案件有助於更快地逮捕兇手，挽救生命。

The Golden State Killer remained unidentified for over 40 years.

40 多年以來，金洲殺手的身分不明。

Eventually police created a fake profile on a genealogy website, uploading The Golden State Killer's DNA.

最後，警方在家譜網站上創建了假身分，並上傳金洲殺手的DNA。

They found a handful of third and fourth cousins, built up a family tree.

他們找到了幾個第三代和第四代的表親，建立了家譜樹。

And were able to narrow it down to just a few suspects.

並因此將調查範圍縮小至幾名嫌疑犯。

In April 2018, Joseph James DeAngelo was finally arrested.

2018 年 4 月，金州殺手 Joseph James DeAngelo 終於被捕。

In connection with 13 murders, over 50 rapes, and 120 burglaries.

他與 13 起謀殺案、50 多起強姦案和 120 起竊盜案有關。

The term serial killer only entered popular usage during the case of Ted Bundy.

連環殺手一詞是在調查 Ted Bundy 的案件時才開始廣泛使用的。

Between 1974 and 78 he murdered over 30 young women across 7 states.

1974 年到 1978 年間，他謀殺了 7 個州共 30 多名年輕女性。

Multiple states had separate investigations, all looking for a man of similar description.

這幾州各自展開調查，都在尋找一名外貌相似的男子。

With the same car, same victim profile, committing murders in the same way.

同樣的車、同樣的受害者和同樣的謀殺手法。

These investigations didn't combine forces until after he was arrested.

各州的調查在他被逮捕之後才被串聯再一起。

It was a hard lesson in the importance of communication.

這個慘痛的教訓讓他們明白了溝通的重要性。

Departments of the FBI were set up to tackle these new types of murderers, using centralized databases.

聯邦調查局成立了多個部門，運用中央資料庫來對付這類新型謀殺罪犯。

If police suspected a serial killer they would now submit...

現在如果警方發現了連環殺手的嫌疑犯，他們會提交......

A Violent Criminal Apprehension Program Report, or ViCAP.

暴力犯罪緝捕計畫，簡稱ViCAP。

This asked for information about the types of victims, witness descriptions...

要填寫的資訊包括受害者的類型、目擊者的描述......

Locations, the time between murders, staging of the crime scenes —

犯罪地點、不同謀殺案件的時間差、犯罪現場的場景 —

Anything that could be characteristic to an individual killer.

任何可能與連環殺手有關的特徵。

All reports from across the country would be compared to each other.

所有來自全國各地的報告都會被進行比對。

Looking for patterns and similarities between cases.

尋找案件的模式和相似處。

ViCAP was pretty successful and is still used today.

ViCAP 系統非常成功，至今仍在使用。

Although it's changed a lot and has been plagued with issues technical and political.

雖然它不斷地被改善，並持續受技術和政治問題所擾。

Nevertheless, it taught us that combining resources and intelligence is vital to catching serial killers.

然而，它讓我們明白了整合資源與情報是逮捕連環殺手的關鍵。

Organizations like Interpol now share data across multiple countries, widening the net even further.

像國際刑警組織這樣的組織現在在多個國家之間共享數據，擴大緝捕罪犯的範圍。

Police aren't the only ones to change. So have we.

改變的不只是警方，還有我們。

Hitchhiking has all but died out, people speak to strangers less.

幾乎不再有人搭便車，人們也很少跟陌生人講話。

And young women rarely walk alone in the woods anymore.

而且年輕女性很少在森林裡獨自行走。

The thought of maybe being murdered by that guy behind you, has become increasingly common.

「可能被身後的人謀殺」的想法逐漸深植人心。

We take more precautions and less risks.

我們採取更多預防措施、避免風險。

Yet ultimately, serial killing declined because technology, science...

但連環殺人案減少主要歸功於科技......

And police procedure are catching murderers sooner.

以及警察辦案的程序，更快抓到兇手。

Potential serial killers are being caught and imprisoned immediately after their first murder.

潛在的連環殺手在第一次犯案後立即被捕入獄。

Or for a different crime, before they even have a chance to start killing.

或在他們有機會殺人之前，因為其他罪行被捕入獄。

And once they're in prison, they're more likely to stay there.

而一旦他們入獄後，就可能永遠待在裡面。

Prison sentences for violent crimes have gotten longer and parole has been reduced.

暴力犯罪的刑期延長、假釋減少。

Dr. Mike Aamodt from the Serial Killer Database says...

連環殺手資料庫的 Mike Aamodt 博士表示......

"Not quite 20% of our serial killers were people who had killed, gone to prison...

「在我們的連環殺手之中，只有不到 20% 因為殺人入獄的人......

Been released and killed again."

於被釋放後再次殺人。」

By the way, the Serial Killer Database is fantastic.

順帶一提，連環殺手資料庫令人太開眼界。

They have a report comparing IQ scores to killing methods. I'll link it with the sources below.

他們有一份比較智商分數和殺人手法的報告。我會把連結放在下方資訊欄。

Since 1987, there's been a 85% reduction in the number of US serial killers.

自 1987 年以來，美國連環殺手的數量已經減少 85%。

There's still plenty around, between 20 and 30 are caught a year.

連環殺手還是很多，每年大約有 20 到 30 名連環殺手被捕。

But when they are caught, they have a lot less victims.

但他們被逮捕之後，受害者比以前少了很多。

If Ted Bundy was around today, he wouldn't have been able to kill so many women, and he wouldn't have gained the same notoriety.

如果 Ted Bundy 現在還活著，他可能沒辦法殺死那麼多女人，也不會得到同樣的惡名。

To be a famous serial killer now, you've really got to push the boat out.

現在想當聲名狼藉的連環殺手，你得大費周章。

Your common old garden serial killer just doesn't make national headlines anymore.

普通的花園連環殺手(園藝師殺人事件)根本就上不了新聞頭條。

There have been lots of key developments, evidence, and change of procedure

that you can directly point to, to explain the reduction in serial killing.

But the real mystery isn't "where did all the serial killers go?"

It's "where did they come from?"

A key difference between serial killing and your average homicide,

is that victims and their killers are usually strangers.

Serial killers often seek out areas where they're unlikely to know people.

Kevin Haggerty and Ariane Ellerbrok make a case for the 'Society of Strangers.'

The idea being that the 50s and 60s saw unprecedented migration to urban areas.

People went from growing up in small towns where everyone knew everybody,

to cities were the vast majority of the people they met were unknown.

This provided potential serial killers with a wide pool of victims,

while at the same time granting them anonymity.

Another theory is that serial killers just began copying each other.

The 60s also saw the popularization of TV news, true crime documentaries, books, and magazines.

Mass communication allowed stories about the latest murder to spread, gripping the nation like a TV soap.

By the time Ted Bundy appeared on the scene, a celebrity culture had grown around serial killing.

A young would-be serial killer may have found the potential glory and attention intoxicating.

In summary:

the 60s saw huge societal shifts that led to a monumental increase in serial murder,

and it took 40 years for science, technology, and police to catch up.

It would be arrogant to think we now have serial killing under control,

many countries around the world are still seeing continued growth.

The recent decline is a Western phenomenon.

There's no reason it couldn't increase again. After all, we're currently undergoing our own huge societal shifts.

More and more serial killers today find their victims online

and are able to be a lot more careful about their movements and meeting places.

The serial killer handbook is constantly changing, and we need to change with it.

In this video I said the word "sewial killer", "serial killer" 34 times, "murder" 13 and "rape" twice.

There's no way it isn't getting demonitised by YouTube.

So I would like to say a big thank you to Joe Chamberlain and all my supporters on Patreon,

who are the only reason I'm able to make videos like these.

If you want to support the channel, check out the link, and thank you for subscribing.