now for over 20 years.

現在已經超過20年了。

Although it can be really intricate

雖然它可能真的很複雜

and time-consuming work,

和耗費時間的工作。

it is just so fantastic when you actually make a match.

當你真正做一個匹配的時候，它是如此奇妙。

Most of us probably think that

我們大多數人可能認為，

we've got a pretty good understanding

我們已經有了相當好的理解

of the basic principles

的基本原則

of forensic science.

的法醫科學。

We binge on true crime TV series,

我們狂歡於真實犯罪電視劇。

we read and buy huge numbers of books,

我們閱讀和購買大量的書籍。

and obsessively download true crime podcasts,

並痴迷地下載真實犯罪播客。

trying to figure out whodunnit.

試圖弄清誰是凶手。

But there are some things about forensic science

但有一些關於法醫科學的事情

that you will probably only know

你可能只知道

if you're an insider.

如果你是一個內部人士。

Let's start with some basics.

讓我們從一些基本知識開始。

Where does all the information a forensic scientist needs come from?

法醫科學家需要的所有資訊來自哪裡？

Well, everywhere really.

好吧，真的到處都是。

In the early 1900s,

在20世紀初。

French criminologist, Edmond Locard,

法國犯罪學家埃德蒙-洛卡。

declared that every contact

宣佈每一次接觸

leaves a trace.

留下痕跡。

This forms the basis

這形成了一個基礎

of what is now called 'Locard's exchange principle'

現在被稱為 "Locard的交換原則 "的東西

which says that whatever you interact with,

其中說，無論你與什麼人互動。

you leave something behind and take something away.

你留下了一些東西，也帶走了一些東西。

One of the areas of forensic science where this is particularly applicable

這一點特別適用於法醫學的一個領域

is forensic botany.

是法醫植物學。

There are around 390,000 different species of plants in the world,

世界上大約有390,000種不同的植物。

each with its own pollen type,

每個人都有自己的花粉類型。

and when it comes to crime scenes, pollen can really tell a story.

當涉及到犯罪現場時，花粉確實可以說明一個問題。

It's all around us, it's on the ground,

它就在我們周圍，它就在地上。

if you walk on soil or vegetation

如果你在土壤或植被上行走

you pick it up, inevitably you pick it up.

你拿起它，不可避免地你拿起它。

Patricia Wiltshire is a forensic ecologist,

帕特里夏-威爾特希爾是一名法醫生態學家。

she uses pollen to help solve crimes.

她用花粉來幫助破案。

Unlike other forms of evidence,

與其他形式的證據不同。

pollen isn't easily washed away.

花粉不容易被洗掉。

It gets into clothes and it can often be found on shoes

它可以進入衣服，而且經常可以在鞋子上發現它。

or on the foot pedals in cars.

或在汽車的腳踏板上。

Pollen and spores are too small to be seen by the naked eye,

花粉和孢子太小，無法用肉眼看到。

so criminals rarely realise

所以犯罪分子很少意識到

that they've picked them up at a crime scene.

他們在一個犯罪現場撿到了這些東西。

Pollen and spores are produced by plants and fungi.

花粉和孢子是由植物和真菌產生的。

They grow in specific places,

它們生長在特定的地方。

so you know very well that this plant will grow in this soil,

所以你很清楚，這種植物會在這種土壤中生長。

that plant will grow in that soil,

該植物將在該土壤中生長。

and because of that, we can predict where they are from.

也正因為如此，我們可以預測他們來自哪裡。

In one particular case of an attempted murder,

在一個特殊的謀殺未遂案件中。

this man tried to strangle a girl underneath a lamp post

這名男子試圖將一個女孩勒死在燈柱下

and he said he hadn't been there, of course,

他說他沒有去過那裡，當然了。

but by taking his clothing apart,

而是通過拆開他的衣服。

I showed that he'd bumped up against a fence with his left shoulder,

我表明他的左肩撞到了柵欄上。

that he'd dragged her through a hedge,

他把她拖進了樹籬。

that he'd knelt, and so on.

他已經跪下了，等等。

And because I sampled the crime scene in detail,

而且因為我對犯罪現場進行了詳細的採樣。

I could see where bits of his body had been

我可以看到他身體的碎片被放在哪裡

so I could actually reconstruct what he did at the time.

所以我可以實際重建他當時的工作。

There are other ways in which nature can help forensic scientists

大自然還可以通過其他方式來幫助法醫科學家

determine when a crime was committed.

確定犯罪發生的時間。

Insects, for example, can provide a lot of information

例如，昆蟲可以提供很多資訊

if you know what to look for,

如果你知道要找什麼的話。

as forensic entomologist, Amoret Whitaker, explains.

正如法醫昆蟲學家Amoret Whitaker所解釋的那樣。

When you die your body starts to break down and decompose

當你死的時候，你的身體開始分解，分解。

basically straight away. And so your body starts giving off certain odours

基本上是直接的。是以你的身體開始散發出某些氣味

and those are very attractive to blowflies.

而這些對吹蠅來說是非常有吸引力的。

If we can work out how old the larvae are that are feeding on the body,

如果我們能算出以身體為食的幼蟲有多大。

then we can work out the minimum time that that person must have been dead.

那麼我們就可以算出這個人至少應該死了多久。

The colder it is, the slower the larvae develop,

天氣越冷，幼蟲的發育就越慢。

the warmer it is, the faster they develop.

天氣越暖和，它們的發展就越快。

Really, the shorter the time span since the death,

真的，死亡後的時間跨度越短。

the more accurate we can be.

我們就可以做得越準確。

Remember Edmond Locard, the French criminologist we mentioned earlier?

還記得我們之前提到的法國犯罪學家埃德蒙-洛卡嗎？

His contribution to forensic science

他對法醫學的貢獻

didn't end at "everything leaves a trace".

沒有結束在 "一切都留下痕跡"。

He developed and contributed to various methods of forensic analysis,

他開發了各種法醫分析方法並做出了貢獻。

including dactylography, the study of fingerprints.

包括指紋學，對指紋的研究。

The interpretation of evidence has changed a lot

對證據的解釋有了很大的變化

since I became a crime scene examiner 20 years ago.

自從20年前我成為一名犯罪現場檢查員以來，我就一直在關注這個問題。

Back then, if I examined a car whose door had been broken open

那時，如果我檢查一輛車門被撞開的汽車

to gain entry, and the only evidence I found

我發現的唯一證據是

was a fingermark on the outside of the driver's door,

在駕駛室的門外有一個指印。

I could reasonably expect

我可以合理地期望

that if the fingermark was identified for someone,

如果指印被認定為某人。

then that person would eventually be charged with the offence

那麼這個人最終將被指控犯有罪行。

and the case would go to court.

並將此案提交法院審理。

However, things are now very different.

然而，現在的情況非常不同。

If the same fingermark was found today,

如果今天發現了同樣的指印。

especially in a relatively non-serious case such as this,

特別是在這樣一個相對不嚴重的案件中。

there would be a strong likelihood that it wouldn't go to court

很有可能不會上法庭。

and this is because the Crown Prosecution Service, or CPS,

這是因為皇家檢察院，即CPS。

they need to be satisfied that there is sufficient evidence

他們需要確信有足夠的證據

to provide a realistic prospect of conviction.

以提供現實的定罪前景。

Their argument for not prosecuting

他們不起訴的理由是

based on the fingermark on the outside of the vehicle

根據車輛外部的指路標誌

might be that anyone could have walked by and leaned on the vehicle,

可能是任何人都可能走過並倚靠在車輛上。

leaving the mark.

留下痕跡。

In the past,

在過去。

defence barristers argued about who the evidence belonged to,

辯方律師就證據的歸屬進行了爭論。

but now they focus on how the evidence got there.

但現在他們關注的是證據如何到達那裡。

Could the evidence have been left

證據會不會是被留下的

by someone other than the person breaking into the car?

是由闖入汽車的人以外的人所為？

If there is any possibility it could be someone else,

如果有任何可能，那就是其他人。

then the CPS tend not to take these cases to court.

那麼，CPS往往不會將這些案件提交法庭。

Forensic science is constantly evolving.

法醫學是不斷髮展的。

In the future, it's possible that many crimes will be solved

在未來，有可能很多犯罪都會被破獲

before they've even been committed,

在他們還沒有實施之前。

as predictive software will mean that police forces

作為預測性軟件將意味著警察部隊

will be able to anticipate when and where a crime is likely to take place

將能夠預測到犯罪可能發生的時間和地點

and even who's likely to commit it.

甚至是誰有可能會犯。

Then there's our microbiome, the tiny microbes in our gut,

然後是我們的微生物組，我們腸道中的微小微生物。

which, according to a new study Harvard,

其中，根據哈佛大學的一項新研究。

can identify us as individuals just like a fingerprint.

可以像指紋一樣識別我們的個人身份。

Despite the rapidly changing world of forensics,

儘管法醫的世界在迅速變化。

Linda says that there's one thing

琳達說，有一件事

that good forensic scientists never forget...

好的法醫科學家永遠不會忘記...

That we're dealing with real people's lives,

我們面對的是真實的人的生活。

and we need to ensure that we work

而我們需要確保我們的工作

in an objective and unbiased way,

以客觀和不偏不倚的方式。

because if we get it wrong, it's people's liberty that's at stake.

因為如果我們弄錯了，人們的自由就會受到威脅。