Original subtitles

NARRATOR: They are the murders that shook the nation...

REPORTER: The savagery of this murder

has shocked even the most hardened detectives.

REPORTER: He was attacked by this bus stop by a racist mob.

REPORTER: This flat was the scene of a horrific killing.

For decades, the truth lay hidden, and the killers evaded justice.

Until one woman took up the hunt.

Angela has solved some of the biggest cases in British history.

Dr Angela Gallop is a world-leading forensic scientist.

I've clone a lot of work with forensic scientists,

but she's the best.

She led the team and set the standard.

She put the bar where it was.

She's helped solve hundreds of high-profile cold cases,

finding clues where others have failed.

Without the forensic input,

the murder would never have been solved.

Now Dr Gallop is opening her extraordinary casebook

to reveal the forensic secrets

behind some of the country's most infamous crimes

and how they caught the killers

who thought they'd got away with murder.

It's a puzzle that you have to solve.

Every contact leaves a trace.

It's just whether or not we are clever enough to find it.

NARRATOR: Tonight, the racist murderers of a teenager

had remained free for well over a decade.

Stephen Lawrence was brutally killed.

It must be the most high-profile criminal case

in recent criminal justice history.

It's a despicable attack.

NARRATOR: Could forensic science

finally find the clues to bring the killers to justice?

We were going to give it our very best shot.

In all murder cases,

the one that nails you in the end is the forensics.

It was a sort of murder you'd expect

in the Deep South in the States in the '50s or '60s,

not in 1990s South London.

Stephen Lawrence was brutally killed

by a group of racist thugs.

They came in to attack any Black youngsters

for no reason other than clue to the colour of the person's skin.

It was like an old-fashioned lynching.

Stephen Lawrence, a teenager at the time,

was with his friend Duwayne Brooks,

and they were waiting at a bus stop

in Well Hall Road in South East London.

They'd just missed a bus to get home...

...and it was a "wrong place at the wrong time,"

where they went on the turf of a racist gang.

And they were subjected to an unprovoked racist attack...

...by a number of young white men.

Er, and he wasn't able to be saved, you know?

Dead, really, when he got to hospital.

A mother goes to the hospital and finds a dead body of her son.

How painful can that be?

NARRATOR: Stephen Lawrence's murder

was a despicable crime which shocked the nation.

But the investigation which followed

was to cause more pain for the family

and bring shame on Britain's largest police force.

Stephen's suspected killers remained free.

Thirteen years after the murder,

the evidence to catch the racist gang still eluded the police.

A new team of detectives was brought in,

and they turned to Dr Angela Gallop

to carry out a detailed review of the forensics.

So, it all came down to science.

It was gonna come down to science.

NARRATOR: Angela Gallop is one of Britain's top forensic scientists.

She has helped solve hundreds of cases since the 1970s.

Although concentrating on the science of crime detection,

she has always been driven by a keen sense of justice.

I think at a fairly early stage,

I got absolutely gripped by forensic science and by what it could do.

Ancl it's partly about fairness, and that matters very much to me.

I think a lot of this sense of justice

probably came from our mother.

She was a very thoughtful person,

and we were kind of brought up with this notion

that that is fair, and that is not fair.

You could see very strongly in Angela that she is, I think,

driven very much by this sense that justice should be clone.

You know, bad people should be punished,

and good people should not be punished.

Ancl that takes her, interestingly, to forensic science,

which is exactly what forensic science does.

Society gets better justice.

NARRATOR: Now Angela needed to help solve a case

which had shocked a nation.

A case which continued to highlight racial injustice in society

and in law enforcement.

It must be the most high-profile criminal case

in recent criminal justice history, I would think.

Ancl of course we were delighted

to accept what was a great challenge, actually,

cos so much had been talked about and thought about this case.

In a way, it was quite unlike any of the others.

NARRATOR: Angela went back to the case files

to get an initial understanding of the attack.

Stephen and Duwayne Brooks

had been minding their own business at the bus stop

when they'd caught the eyes of a gang of five white youths,

evidently racist in the language they were using.

Ancl Stephen got surrounded by this gang,

kicked, punched and knifed twice.

Stephen was fatally injured in that attack

while him and Duwayne Brooks were trying to escape their attackers.

NARRATOR: Angela brought together a team to review the evidence.

Forensic examiner April Robson, hair evidence expert Deb Hopwood...

...and fibre and particle examiner Roger Robson.

The scientists knew this was probably gonna be the last time,

erm, we were gonna get to try and find the evidence.

Everybody else had failed,

and it just takes that little bit of extra perseverance, really.

If the evidence is there, we should be able to find it.

We were aware that there was an enormous amount of additional trauma

that the family had been through

because of all the various legal stages and enquiries and so on.

So we were going to give it our very best shot.

NARRATOR: Four years before Angela had joined the cold case team,

a judge had led a public inquiry into the original investigation.

REPORTER: This was supposed to be the final word

on a disastrously incompetent police inquiry.

NARRATOR: After hearing extensive evidence,

Lord MacPherson had reported

that the Metropolitan Police's search for Stephen's killers

had been marred by "professional incompetence"

and "institutional racism."

Key, now, to getting justice for Stephen

would be Angela's partnership with the experienced detective

in charge of the new inquiry, Clive Driscoll.

Investigating a murder is like a thousand piece jigsaw,

but the jigsaw's been thrown here, there and everywhere,

so the scientists have some of the pieces,

the police have some of the pieces,

the witnesses have some of the pieces,

some of the pieces are exhibits.

Ancl that's exactly what happens.

You're just putting it all together so the jury can see the picture.

NARRATOR: For both Clive and Angela,

the first piece of the jigsaw was the crime scene.

Nearly 20 years on,

they are meeting up again at the spot where Stephen was attacked.

I always feel quite sad when I come back here, funnily enough,

because it's almost like a memory.

Even when I drive through here occasionally,

I always get a bit of a sad feeling, really. Yeah.

Young Stephen lost his life here, and...

It's the normality of it

which makes it even more horrific in a way, isn't it?

A nice suburban street

and that sort of awful sort of thing that can happen.

If we look over there, that's Dickson Road.

That's where the attack took place,

and if you look down the road to the zebra crossing,

that's where the five or six lads ran across the road.

Ancl once the attack took place, they then ran, crossing over,

and Stephen got just a bit further down the road there,

where, in fact, his injuries caused him to lose his life.

Stephen wouldn't have known what was about to happen to him.

He had headphones on.

They were running across the road,

and they all actually just descended like a pack of wolves.

Stephen was stabbed twice.

The first injury actually went down here by the clavicle

and severed the artery there.

The next injury came up there and actually severed another artery.

He had lots of bruising, he had lots of other marks on him,

and you've got someone who's obviously,

as we all would be if we were attacked,

your heart goes faster.

Then he did the most normal, natural thing you could ever do.

He's running away from danger which made his heart pump faster.

The worst thing he could have clone

but so understandable why he'd clone it.

So understandable. Absolutely.

NARRATOR: But in 2006, when taking on the forensics for the cold case,

Angela was aware that there was a problem.

In the 1990s, there had been no effective scientific evidence

leading to Stephen's killers.

Angela knew this because she had already investigated

and found nothing.

Stephen's parents, Neville and Doreen Lawrence,

had had their doubts

about the competence of the police investigation

from the very beginning.

You've got to remember there were stereotypes of young Black men.

He didn't fit the stereotype,

and it's not a stereotype that I was aware of.

I knew that police and the community and society

suggest a stereotype of young Black men.

Ancl he didn't fit that at all.

Stephen was a high achiever, he was gonna be an architect.

He hadn't been in any sort of trouble,

he was incredibly well-loved

and liked by his immediate family and those around him.

So it wasn't long before the family started to become a bit cynical

about the police response and what they were doing,

and then they came to the conclusion

that perhaps it was because it was a Black man who had been killed,

and they were a Black family,

that somehow they were not getting the treatment

that others in the community got.

If it had been a white boy,

they would have surrounded the Black community,

they would have arrested as many Black boys as they could,

and they would not stop until they get the killer.

NARRATOR: Although arrests were made about two weeks after the murder...

...the suspects were soon released.

Well, I believe in fairness,

and I don't think what happened today is fair at all.

When it became clear

that the CPS were not going to progress with a prosecution,

the Lawrence family decided

that they were going to take out a private prosecution,

and that was when I was contacted in 1995 by lmran Khan, their solicitor.

In all murder cases, the key bits of evidence,

the one that nails you in the end, is the forensics.

If you get the forensics right,

all of the other stuff is icing on the cake.

Ancl so we had to look at the forensic evidence

to see what could be found.

I was asked to go and check the work

that had been clone at the police laboratory,

just to see whether everything had been clone that could've been clone.

Ancl the searches at that time

focused very much on tiny textile fibre fragments

that could have been transferred from the suspects' clothing

to Stephen's clothing.

It was reason that, in the time that he ran down the road,

not many of any fibre fragments,

which would have been transferred to him immediately beforehand,

would have had time to drop off and be lost,

whereas because the clothing from the suspects hadn't been seized

for about two weeks after the attack,

anything that might've been transferred to them

on the night in question could easily have been lost.

Ancl so the focus was very much on looking for suspect fibres

on Stephen's clothing.

Ancl so I checked those, but in the end of the clay,

didn't really come up with any more evidence

than the original scientists had found.

NARRATOR: This lack of forensic evidence

had dealt a massive blow to the family's hopes

of bringing a prosecution against the suspects.

And when the judge ruled

that evidence from Stephen's friend Duwayne,

identifying the suspects,

was inadmissible, the case collapsed.

We knew then that was it. We couldn't prosecute ever again.

NARRATOR: The three men acquitted in the private prosecution

were now protected by law from ever being tried for the murder again.

And there appeared to be no forensic evidence to catch the murderers.

Many now believed that the killers of Stephen Lawrence

would never be brought to justice.

But the one thing

that I've learnt about forensic science over the years

is that you never say never.

NARRATOR I It was 2006.

Forensic expert Dr Angela Gallop had been called in to find evidence

in one of the most notorious cold cases in British history.

The racist murder of Stephen Lawrence.

Stephen had been stabbed to death

while waiting for a bus in South London

in April 1993.

Angela found that the senior cold case detective, Clive Driscoll,

believed his new research at the crime scene

had given him a fresh insight into the murder.

I used to come down here a lot.

I spent loads of time walking up and down

and trying to work out where we were and what had happened.

Ancl one of the things that I quickly worked out was there were...

If you took the longest time, someone said it was a minute,

if you took the shortest time,

someone said it was over and clone with in a couple of seconds.

And, erm... we re-enacted it, and we formed the opin...

Ancl I still believe this to this clay,

that it was about between 15 and 23 seconds,

which is, for your world, transference...

Yeah. ..and people...

It's a long time! It's a long time, yeah.

Ancl I felt that,

you know, certainly, from what I'd read from,

you know, the previous scientists...

that they'd... that they'd always felt it was a brief attack.

Well, I didn't.

And, in fact, Professor Gallop immediately said,

"Yeah, this isn't a brief attack.

"There's greater opportunities

"for transference of all types of material."

You could begin to see that, actually, the attack

would have taken place over a bit of a period of time,

and there would have been plenty of opportunity for,

particularly, contact between clothing of the assailants

and... and Stephen's clothing.

And... And so, that was ream], for us,

the start of being able to look at this

in a different way with Professor Gallop's team.

NARRATOR: Angela and her team now had to explore the idea

that there had been greater contact between the attackers and Stephen

than first assumed.

She decided to focus on the possible transfer

of textile fibres from clothing.

Textile fibres are an incredibly important source

of forensic evidence, much underrated, I always think.

Because all the time, most of our clothing

is shedding these tiny fragments as we move about,

as we come into contact with other surfaces.

They can be a fantastic way of showing a connection

between clothing of one person, clothing of another.

Some fibres you can see,

but the vast majority are so small and microscopic,

you just wouldn't know what's sat on the surface of your own garments,

and what then has potential to transfer to somebody else's.

Which is a nightmare for a criminal, it's great for a forensic scientist.

We were aware that the defendant's clothing hadn't been seized

for at least two weeks after the of fence.

So arguably, you would expect most of the evidence to have been lost.

However, Stephen's clothing had been seized and packaged immediately,

so hopefully they were a good source of potential evidence,

even though we were aware

that they had already been previously examined.

My role was to re-examine all the exhibits.

We started off with Stephen's exhibits.

So, again, we taped the exhibits,

and then we looked at his exhibits for blood.

Ancl it was only then,

when I started looking at the tapings from Stephen's clothing,

that I realised that what I was identifying

was a lot of red fibres, red cottons, and red synthetics.

Ancl at the time, it wasn't obvious where they were from,

but then we realised that Stephen's polo shirt,

that he was wearing three or four layers down, were shedding fibres.

What it told us was that these red fibres

might be worth looking for on the suspects' clothing.

Because they were on the outside of his outer clothing,

erm... and therefore, available for transfer to anybody

who came into contact with him.

NARRATOR: This was the initial breakthrough

that Clive Driscoll needed.

I can remember the phone call because she... she actually said,

"We found thousands," was her words, "of red fibres."

Ancl I said, "Oh, it's probably the ambulance blanket."

Ancl she said, "No, it ain't." She said, "It's a different colour."

That was his third shirt... was shedding all over.

So, if it shed from the third shirt outwards,

the chances of it going further on other people's clothing

must be an opportunity.

In one way or another, the fibres from the polo shirt

were transferring to other garments that he was wearing,

and therefore they were sitting on the surface of his jacket,

giving us the potential

to then look for those red cotton and red polyester fibres

on the assailants.

NARRATOR: But the team would need to analyse the suspects' clothes...

thread by thread.

We take an exhibit,

and in a controlled laboratory environment,

the item of clothing comes out of the bag.

We usually have it laid on a piece of brown paper

just to collect anything that might fall off.

And then we meticulously work our way across the garment

with pieces of tape,

and each piece of tape is then sealed

under an acetate sheet.

From there, we then used low power microscopy

to look at each of those pieces of tape,

mark up fibres that may be of interest,

and then individually remove them one by one.

NARRATOR: Among the clothes

were items belonging to two of the original suspects,

David Norris, and his friend, Gary Dobson.

But Dobson had already been acquitted of the murder

in the trial which followed the private prosecution

brought by Stephen's family.

I started looking at Dobson's jacket for these red fibres,

and I found 11 fibres that were very similar

to Stephen's polo shirt.

They were then sent for additional analysis.

So I then looked at the sweatshirt of David Norris

and found one red fibre that was similar,

and again, that was sent off for analysis.

NARRATOR: The analysis found that these fibres

matched Stephen's red polo shirt.

Ancl that led us to think,

"Well, if we're finding these fibres,

"you know, from Stephen's clothing on the suspect,

"well, let's look for some other types of fibres

"from his clothing on them."

NARRATOR: The team then found fibres from Stephen's jacket

on Gary Dobson's clothing.

And green fibres from Stephen's corduroy trousers

on the sweatshirt that David Norris had been wearing

on the night of the attack.

Now we were beginning to amass quite an amount of textile fibre evidence.

NARRATOR: But textile fibre evidence alone

would not be enough to prove murder.

And despite many more days and weeks hunched over a microscope,

the team could find nothing more on the tapings

from Dobson's jacket or Norris' sweatshirt.

So if they wanted to pursue this lead further,

they needed a moment of inspiration.

These items of clothing have been in packaging,

and they've been taken out of packaging, put back into it,

lots of times over the years.

And, so, maybe, what we should be doing

is having a look at the original packaging itself.

NARRATOR: The team began to carefully remove

tiny pieces of debris from corners of the packaging

in which the suspects' clothes had been stored.

They were searching for more red fibres from Stephen's top.

But they found something which appeared to be even more crucial.

So, we went into every nook and crevice

just to make sure we got everything out of there.

Ancl we were pretty surprised to find a flake of blood.

NARRATOR: The blood in the bag was attached to tiny blue fibres

which didn't match the clothes that had been stored there.

Finding that tiny fragment of blood joined to a fibre of interest

was huge.

Almost something that you couldn't imagine would happen

other than in a drama.

Blood had never been found before, so it was a great eureka moment.

NARRATOR: It was the first blood evidence to be found in the case.

And it had been found in a bag...

containing the jacket from the suspect...

Gary Dobson.

NARRATOR: Forensic expert Dr Angela Gallop and her team

were working on the re-investigation

into the 1993 murder of teenager Stephen Lawrence.

Painstaking searches of two of the suspects' clothes

had found fibres from one of Stephen's tops,

suggesting the men may have been present at the attack.

Then, while searching for more fibres

in packaging containing evidence,

the scientists found something even more intriguing.

We came across a flake of blood,

running through which were two textile fibres.

Ancl looking at these two fibres, they were both of blue acrylic.

We immediately went and compared them with Stephen's clothing

and discovered that they matched the fibres constituting his cardigan,

he was wearing a blue acrylic cardigan at the time.

Ancl this flake of blood,

the packaging this had come from was from Gary Dobson's jacket.

NARRATOR: The blood flake was sent for a DNA test.

While waiting for the result,

the team continued its search of the clothes.

Finding a flake of blood like that in packaging,

we would expect to find the blood stain from which it originated

on the jacket itself.

Ancl so we went back to the jacket,

which had already been examined several times

by the original scientists, by us, probably more than once.

So we knew whatever the remains of this blood flake looked like,

it would be tiny.

So, I started to examine Dobson's jacket

in much more detail under the microscope.

And the tayimgs that we'd taken

gave us the areas to target very specifically.

Ancl so this was a bit of job to do, and particularly, in this case,

because this jacket was grey coloured, and the grey came about

because there were sort of two individual constituent fibres.

There were black fibres and white fibres,

and so together, to the naked eye, they looked grey,

but actually, under the microscope, they looked black or white.

Ancl so searching this jacket

was an absolute nightmare under the microscope

because your eyes were constantly adjusting

between the black fibres and the white fibres.

And so, it was... quite a tiring process to do.

This is painstaking, this is new,

they were not going to leave any fibre unlooked at.

And so, it was described to me as a process that would take weeks

going through every single stitch of a jacket

to see whether there was any blood on it.

It showed the thoroughness with which the forensic team worked.

NARRATOR: But the team's patience...

paid off.

I found a very tiny... What looked like a bloodstain

on the back of the collar of Dobson's jacket.

That spot of blood was miniscule,

and it could easily have been missed.

But the fact that the forensic team put that amount of time,

and the resources were put in,

indicates the strength and depth of that team and their commitment

in making sure that that evidence saw the light of day.

NARRATOR: If it was a bloodstain from the murder,

why was it on the inside back collar of the suspect's jacket?

It seemed an unusual place.

But Angela had studied the way blood is transferred

during a violent assault with a knife.

Being inside the back of the neck of the jacket

was not particularly surprising,

because that is the sort of place

that if you're going to get blood or tiny blood droplets

flicked off a knife that's been used to stab someone,

it may very often go down the back of clothing

because as the hand comes back from the first injury,

and it reaches the end of its trajectory,

there can be a little judder before it's brought forward again

for another... another blow.

Ancl that's the point at which tiny droplets of blood

can come off the knife blade

and then go onto the back of the perpetrators' clothing.

NARRATOR: As April and Angela waited for the DNA result on the blood,

their colleague, forensic hair expert Deb Hopwood,

was hard at work in another laboratory.

I was presented with what we call the retained material,

and these were in the form of tape lifts

that were taken during the original examination of the items.

Tape lifts taken during the re-examination

and also debris that had been collected along the way

from these examinations.

We examined over 600 hairs

in relation to the retained material from Stephen's clothing.

On the Norris and Dobson,

we were looking at about 1,500 hairs,

so it was a massive undertaking.

We noticed on Stephen's clothing

that there were quite a lot of short, cut hairs

of the type that you get when you've had a recent haircut.

Ancl so we were quite interested to see

whether any of these could have been transferred to the suspects.

When I looked at the retained materials from David Norris,

there were two short fragments of very deeply pigmented hair

that appeared to me

to be more like they could be Asian or Afro-Caribbean in origin.

Here, we potentially had some very significant evidence.

NARRATOR: Although tiny, one of these two hair fragments

appeared to hold a forensic secret.

One of them was approximately 2mm in length,

and the other was 1 mm.

And when I examined the 1 mm fragment

under high power microscopy

it appeared to have a tiny amount of blood

on the cut end.

But the blood and the hair fragment were just too tiny

to do anything further with.

NARRATOR: So Deb concentrated on the 2mm fragment of hair.

It could be large enough to identify who it belonged to.

But the fact that it was a piece of hair left over after a haircut,

meant there was a problem.

Because these hairs had been cut,

there was no root or any additional root material

that we might generate a DNA profile from.

And our only realistic hope

of getting any further information out of these hairs

was to forward them for mitochondrial sequencing.

NARRATOR: Mitochondrial DNA links only to a person's mother's side

but would still be important evidence.

The hair was sent to the United States

to be analysed in a specialist laboratory.

While the team waited for the result,

April Robson received a message.

The blood she had found on Gary Dobson's collar

had been tested...

and the result was back.

I remember quite vividly

when the reporting scientist came into the room

and asked me to follow him into a quiet room,

and he told me at that stage

that the DNA profile had come back as Stephen's.

I just remember quite a chilling feeling,

erm... because, although we thought it could have been from Stephen,

actually getting that, obtaining that DNA result

was extremely powerful.

I remember we had to check it, double-check it,

and probably triple-checked it

before we actually told the Senior Investigating Officer

about the result.

We passed on the message about the blood

to the Metropolitan Police, and in particular, to Clive Driscoll

who was the Senior Investigator.

At a very poignant moment, he just happened to be

in a memorial service to Stephen at the time.

NARRATOR: The result was confirmed

as the family marked the 15th anniversary of Stephen's death

with a church memorial service.

Clive Driscoll was looking at a photo of Stephen on the altar

when his phone rang.

I was actually looking down the aisle at Stephen,

when I was told that we'd just found Stephen's blood

on Gary Dobson's jacket.

The evidence of blood DNA is the best evidence you can get, really.

The finding of the blood on Gary Dobson's jacket

was a really critical moment in the whole re-investigation

cos here, for the first time in all these years,

we had got blood that could have come from Stephen.

So, Stephen injured and Gary Dobson there at the time.

NARRATOR: There was now fibre evidence

against Gary Dobson and David Norris...

and Stephen's blood on Dobson's jacket.

But there was more to come.

Hair expert Deb Hopwood received a phone call

from the laboratory in America

which had been investigating the tiny piece of cut hair

she had found on Norris' clothes.

The hair...

was a match for Stephen's DNA.

And I have to say that was quite a moment

after almost three years' work

to find such a crucial piece of evidence.

I think the team went home happy that day.

So, now we have textile fibres

linking both Dobson and Norris to the attack.

We've also got some blood on Dobson,

erm... which could have come from Stephen,

and we've got a hair on Norris

which could have come from Stephen as well.

That showed that they were there at the time Stephen was attacked,

and Stephen was murdered.

NARRATOR: The arrests of Norris and Dobson

turned up the pressure on the forensic team

to ensure their evidence was watertight.

They also had a hurdle to overcome...

Gary Dobson had already been acquitted of the murder

back in 1996.

Unless they could persuade a court,

he would not be allowed to stand trial for the same of fence again.

NARRATOR: Dr Angela Gallop and her forensic team

had gathered evidence in the cold case investigation

into the racist murder of Stephen Lawrence,

and two men had been arrested.

Things are never as simple as you imagine.

You think that's the end of it, but it isn't quite.

NARRATOR: One of the men, Gary Dobson,

had already been acquitted of the murder back in 1996.

He was protected by the law of double jeopardy,

which had stood for centuries.

Double jeopardy is a legal principle

which says that once you've been acquitted of a charge

you can never be charged with it again.

So, the state gets one shot at it -

you get prosecuted,

if you're acquitted, that's the end of it.

NARRATOR: But over the years, the case had had an impact on society

and played a major role in changing the law.

In 1997, a national newspaper, the Daily Mail,

had taken the unprecedented step of using its front page

to accuse five men, including Dobson and Norris, of being the murderers.

It was already high profile, but the Daily Mail, I would argue,

running that front page took it onto a whole new level

in terms of the profile of the case.

NARRATOR: The MacPherson Inquiry found that the police

had been institutionally racist

at the time of the original murder investigation.

It also recommended a change in the law of double jeopardy.

Macpherson's report put forward that

in order for the court to allow prosecution to go ahead

it must be satisfied that there is new and compelling evidence,

ie, that it could lead to the conviction.

We were very aware of all that as we were amassing our evidence,

when it reached the point where I think the police and the lawyers

were also happy that it represented new and compelling evidence.

Then that was the time that they considered

that they would have to get the acquittal overturned

to prepare for this new trial.

NARRATOR: The new forensic evidence against Dobson

was put before the Court of Appeal and the judges agreed

that his acquittal should be overturned.

There WAS enough evidence for him to be tried again

for Stephen's murder.

Here's the law, a principle of law that's been around for centuries,

not decades and months, that's been completely overturned.

NARRATOR: But bringing David Norris and Gary Dobson to justice

would depend on the accuracy of the forensics.

REPORTER: 'The two men accused of killing Stephen Lawrence

'were brought to the Old Bailey...'

NARRATOR: Angela's team faced a massive task

to ensure they were ready

for one of the highest-profile criminal trials in history.

You might think that in this particular case

that we just had a few items of clothing from the suspect

and the clothing that Stephen was wearing on the night in question

and that was what we had to look at.

But actually, there was an enormous amount of material to look at.

We had 500 tubes of DNA extract.

There were 250 pots of debris that we'd brushed off

or picked off, or in some way collected from all of the items

that we maker! at. And we transferred those

onto 700 tapings.

So an enormous amount of work was clone in this particular case.

I had to go in on a daily basis for many months

to check all 4,500 fibres.

It can take at least an hour to ensure that each fibre matches

or it doesn't match.

It's a long slog.

This one was probably

the highest-profile case in the country at the time,

so naturally you want to do a good job

and you want to make sure you've covered every avenue.

NARRATOR: It was hard work, but it paid off.

The forensic evidence was at the heart of the six-week trial.

And in January 2012,

a jury found Dobson and Norris guilty of Stephen's murder.

My memory is turning round and seeing two lovely people,

Baroness Lawrence now and Dr Lawrence, crying.

Ancl I can remember just feeling for them,

because this had been years, hadn't it? You know, for them.

It's the beginning, I think, of starting a new life,

because we've been in limbo for so long.

So today is where we can look to start moving on

and just, I don't know, try and get, take control of my life once more.

I can't ever feel elation

because I haven't brought Stephen back, have I?

I haven't brought Stephen back, that's what they would want.

You know, it was a feeling more of sadness

for Baroness Lawrence and Neville Lawrence

because how much they'd suffered.

NARRATOR: David Norris and Gary Dobson received life sentences

for the murder of Stephen Lawrence.

But the other members of the gang who set upon Stephen that night...

remain free.

Yes, there was a sense of, well, what about the others?

But none of us were, certainly Doreen wasn't,

complaining about that.

Ancl I think the way that Clive Driscoll put it,

"Two down, the rest to go."

So it wasn't about just leaving it.

In terms of getting justice for Stephen and his family,

this forensic evidence was absolutely crucial,

absolutely crucial.

Without the forensic evidence,

there would not have been a prosecution in this case,

a conviction in this case.

You can't put too much emphasis on that.

Ancl so what Angela did in getting that material,

putting it in a way that was presentable to the jury,

finding it in the first place,

using the new techniques to obtain it,

that's what led to the prosecution. That's what gave Doreen justice.

The hope I take forward from this case is that

we're just treated equally

and equal resources are given to each case

and they're all investigated on their merits.

Angela Gallop and Clive Driscoll were quite a dynamic duo,

pretty unique, to be honest.

Ancl to be fair, I think Angela had a pretty damn good team

of scientists around her.

Here's Young Stephen.

1974.

I always refer to him as "Young Stephen".

And they say, "Well, he'd be 40-odd now, wouldn't he?"

I suppose he would be now, yeah.

That's how much life he's actually lost.

We didn't give up.

We kept looking even if everybody else had failed.

We had to work to our highest ability

to try to bring some justice for this bereaved family

and to be a part of the team that was able to do that

was just quite incredible.

We lost a nice young man from our society and for me,

I thank the Lawrence family ancl thank Stephen's name

for the advancements and how we've become better.

Ancl we could be better still, but I think that his legacy

will be that we became better.

Over the years, I have been very impressed by the Lawrence family

and how they've made every single effort

to persuade and cajole and basically do everything they could,

everything in their power to make sure that the case

was properly investigated, at the end of the clay.

Ancl so it was a lot of work, but then in the end,

a lot of evidence and most importantly,

it resulted in at least some sort of closure for Stephen's family

and some justice for Stephen himself.

So I think it was a really important piece of work we did.

Subtitles by accessibility@itv.com