All language subtitles for Cold.Case.Forensics.S01E01.The.Murder.of.Rachel.Nickell.1080p.HDTV.H264-DARKFLiX

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 the 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 done 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're clever enough to find it.

Tonight, the traces of a notorious
murder on Wimbledon Common

went undetected for over a decade.

The thought that you couldn't even
go for a walk with your little boy,

in a London park
without being murdered

was just completely horrific.

Someone must have seen something.

There's something wrong here,

there's something that
doesn't add up properly.

How did ground-breaking forensics

track down a serial rapist
and killer

who showed his victims no mercy?

The murder was on the scale
of ferocity and horror,

which I had never experienced before

as a murder investigator.

REPORTER: The body of 23 year-old
Rachel Nickell

was viciously attacked
and sexually assaulted

after walking
with her two-year-old son

and their pet dog,
last Wednesday morning.

The first I heard about
the murder of Rachel

was during the afternoon
ofjuly the 15th in 1992.

Somebody from our news desk
came over and told me

that there had been a murder
of a woman on Wimbledon Common.

REPORTER: A minute search
of the scene resumed today,

officers scouring Wimbledon Common

for perhaps one vital piece
of evidence.

Wimbledon Common
is a well-known beauty spot.

It's very popular with, you know,
with joggers, with dog walkers,

picnickers in the summer.

It's considered to be
a very, very nice place to be,

and it's also considered to be
a very safe place to be, usually.

I vividly remember,

it was a very pleasant, warm,
you know, summer's clay.

Ancl I made my way to the Common...

...and it was a kind of disbelief

that this could happen
in such a busy area.

I knew there would be
hundreds of people walking around.

It's ten thirty in the morning
when her body was found.

You know, someone must have seen
something, I thought.

But nobody had seen anything.

The police investigation
which followed

was to be a disaster.

An attempt to trick a suspect
into a confession

caused pain and heartbreak.

Rachel's family
was left without justice.

Then, in 2002, the police launched
a cold case review

and called in Dr Angela Gallop -

a forensic expert
who has been helping

to solve murders since the 1970s.

Over the years,
Angela has worked on investigations

into many of Britain's
most horrifying crimes.

My first crime scene
was a bit of a shock.

It was one in the series of murders
committed by the Yorkshire Ripper,

and it was such a serious case

because this man was going around
killing all these women.

It was absolutely dreadful.

Ancl it was going to be
the first time

I'd ever seen a dead body.

Ancl I was very nervous about that
because you never know, I think,

to begin with, how you're going
to react, you know, physically.

You've got no idea how your system
is going to cope with it.

In a way, the full horror
of what I was seeing

was just dampened a bit

because I was so keen
on doing my very best,

to pick up the clues that are there,
not miss anything.

Ancl I didn't really have any time
to think too much about

the human and emotional side of it.

I was much more focused on
doing my best at that time,

and as quickly as possible,

and being of as much help to
the police as I possibly could be.

In the decades since,
female victims of male violence

have often been the subject
of Angela's cases.

Could she now help find
whoever had murdered Rachel Nickell

that summer's morning
on Wimbledon Common?

The thought that you couldn't even
go for a walk with your little boy

in a London park
without being murdered

was just completely horrific.

REPORTER: She was sexually assaulted
and stabbed to death.

Her three-year-old son, Alex,
was found clinging to her body.

My first contact with the case

was when the Metropolitan Police
rang up,

and that was in 2002.

So that was about ten years after
the crime had happened.

They said, you know,
"We've failed to find out

"who committed the crime,
and we want a reinvestigation.

"And part of our reinvestigation,
obviously, is going to be forensic.

"And so, we're very interested
in your helping with this."

That's how the whole thing
would have started off.

The first thing that I did

was to get together a team
of scientists

who I thought had absolutely
the right skills and experience,

because obviously this was
going to be a difficult case.

If it had been easier,

it would have been sorted out
already.

I got in April Robson,

who just is a really good examiner.

She doesn't miss anything.

Ancl another really important member
of the team

would be the DNA prof tier,
Andy McDonald.

Ancl Mike Gorn
was kind of waiting in the wings

in case we found anything
that needed a forensic chemist.

Having organised the team that
was going to do the reinvestigation,

then it was very important to get
as much information as we could

about the case before deciding,

you know,
what we might do ourselves.

Ancl so, the police provided us
with all of the case notes

generated by the scientists
who did the first investigation.

Ancl we began to get an idea
of everything that had been clone.

Using the case notes,

Angela went back to the reports
of the first detective at the scene.

There had been a struggle
on the pathway itself

because it was quite muddy.

She was lying a few feet off
the pathway itself.

Ancl once I got up close to her,

I could see that she had been
mortally stabbed,

and she was in a just...

clothing was in
a dishevelled state.

Ancl I could see that...

life probably was extinct.

Ancl the only witness, if you like,
was this terrified little boy

who was in the arms of a paramedic
and in some distress,

and I could see scratches
on his face.

What trauma had he gone through...

...and what terror
had she gone through

to protect her child
whilst being attacked...

...by a person unknown at that stage.

The original investigation
had pursued a man named Colin Stagg

who had been reported
by local people

as resembling a Photofit
of a suspect.

Convinced Stagg was guilty,

detectives launched
a honey trap operation,

sending an undercover
female police officer

to start a romantic relationship
with him,

in the hope
he would give himself away.

There was no doubt
that the nature of the murder,

coupled to, you know,
a certain amount of pressure,

I think, brought to bear
through media channels,

and so forth,
meant that the police felt

that they were under
a great deal of duress

to try and solve
this murder quickly,

which ended up with
a very serious breach of justice.

In fact, they eventually arrested
a man who was entirely innocent.

Police had believed Stagg would
confide in the honey trap officer

and confess to Rachel's murder.

But he didn't.

Nonetheless, in 1994,
he was sent to trial.

It collapsed almost immediately.

REPORTER: Colin Stagg
leaving the Old Bailey

after the case against him
had been dropped.

The judge recognised that there
was never any evidence against me,

no forensic evidence.

No confession evidence.
Nothing at all.

Not only had there been no evidence
against Colin Stagg,

there had been no forensic evidence
whatsoever

to point to any other suspect.

Angela Gallop and her team
would have to search for clues

from a crime scene
which was now almost a decade old.

In cases where people
have been assaulted,

there are a whole variety
of different samples

that are taken from their bodies.

Things like swabs,
particularly from intimate areas,

also tapings taken
from exposed surfaces of the body,

hair combings,

nail clippings, and scrapings
and things like that.

Almost anything where evidence
from somebody with whom the victim

had been in touch
could have become lodged

or from the victim
that could have been transferred

to a suspected offender.

The process of taking tapings,

where adhesive tape
is applied to the skin

to collect small items of evidence,

had been used on Rachel's body.

Angela asked her team
to take a closer look at these.

When I carried out a review
of the DNA results

that had been previously generated
from the body tapings,

I found that no DNA profile
had been obtained from them.

Not only was there no DNA
from any attacker,

there was no trace
of Rachel's own DNA,

despite the fact the tapings

had been taken from intimate areas
of her own skin.

The fact that we obtained
no profile at all

was an unexpected finding to me.

Angela discussed
this alarming loose end

with her lead forensic examiner,
April Robson.

Common sense in this case
should have suggested

that from the area
that it was taken from,

it should have been swamped
with Rachel's DNA...

Yes, yes. Absolutely.
..and nobody thought about that.

When we were faced with a sample

that hadn't given any DNA results
at all,

when it really should at least

have given the result
from Rachel herself

in this intimate part of her body,

then we knew that something
was very wrong.

Because you can't have
that sort of finding

without finding
a proper explanation for it.

You can't have a loose end
like that.

Forensic scientists
don't like loose ends.

So, what had gone wrong?

And could it have caused the police
to mis the real killer?

REPORTER: Detectives
are appealing to cyclists,

joggers and horse riders
who were in the area

on Wednesday morning
between 9 and 11

to help them with their inquiries.

NARRATOR: A decade
after Rachel Nickell

was brutally murdered
on Wimbledon Common,

forensic scientist Dr Angela Gallop
was on the hunt for the killer.

Angela and lead examiner
April Robson

had gone back to
the original forensic test results

and got a surprise.

Previous reports showed that tapings

taken from Rachel's body

had found no DNA at all-

not even Rachel's own.

This immediately set off
a concern in our minds,

because what they were looking for

was these tiny traces
of the offender,

but also captured on the taping

would have been a lot of skin flakes
from Rachel herself,

Ancl they certainly should have got
a DNA result from Rachel's DNA.

But in the event,
they got absolutely nothing.

So this told us that there was
very likely to be something wrong

with the technique they used
or the way in which they used it.

The original tests on the tapings
from Rachel's body

had been carried out
using the best option available

to scientists at the time.

This was a DNA profiling test
called Low Copy Number or LCN.

But more recent prominent cases
have revealed LCN

to be a technique
with severe limitations.

GERRY MCCANN: 'We don't know
what's happened to Madeleine.

'She's still missing,

'and we're still hopeful
that we'll find her.'

In 2007, after
three-year-old Madeleine McCann

went missing
while on holiday in the Algarve,

an LCN test appeared to show traces
of Madeleine's DNA

in the boot of a hire car
used by her parents, Gerry and Kate.

The discovery meant the couple

spent some time
under the suspicion of the police

and the international media.

REPORTER: To prove their innocence,
the couple have kept their hire car

and may have it
independently tested,

hoping to counter
still unconfirmed claims

that Madeleine's DNA is inside.

But the LCN test result
had been unreliable.

The test had found components
which were part of Madeleine's DNA,

but these were far
from unique to her.

In fact, they were so common
they were even shared

by some of the forensic scientists
brought in to review the evidence.

The LCN test could clearly lead

to suspicion falling upon
innocent people.

But could it also lead
to a murderer remaining free?

Back in 2002, as they began their
review of the Rachel Nickell case,

Angela Gallop and her team were
already suspicious of the LCN test.

They wondered if the technique used
by the original investigation

had "swamped" the DNA,
so that no traces had been found.

We repeated some of this work
on the tiny amount of extract

that was left from these tapings

that the original scientists
had made.

Ancl we discovered the same thing -

that if you use the most
sensitive technique,

then you get absolutely nothing.

But if you start diluting
the amount of DNA that you're using,

then you started to get results.

Angela and her team
abandoned the LCN method,

and retested the tapings
using the standard technique.

For the first time,
two DNA profiles began to show up.

We could see that we had
a large amount of DNA

from Rachel Nickell

and a hint of some sort of DNA
from another individual,

potentially a male individual
within it,

but too little to be able to do
anything with.

But at least we had a hint
that there might be something there.

But, of course, we were
rapidly running out of sample.

The skin taping from Rachel

had finally revealed a trace
of male DNA.

Could this be the first hint
of Rachel's killer?

But with only a partial DNA profile

and all the skin tapings
used up in testing,

the team had to turn
to Rachel's clothes

to try and discover more.

My role was to examine
Rachel's clothing

for any potential
extraneous materials

such as fibres, hairs,
trace evidence,

and then to also look at
the blood distribution

to see if that could tell us
anything about the attacker.

We were looking
for very discreet bloodstains

that looked very different
from the overall blood patterns

that were caused by Rachel's blood.

A first search of the clothes
proved unsuccessful.

So the team came up
with an experiment

to try to work out
where the attacker

would have touched Rachel
as he pulled at her clothing.

In cases like this,
where we want to identify

where somebody might have
touched somebody to remove clothing,

we carry out experiments using
black fingerprint powder,

and this will give us
an idea to target for areas of DNA.

And so in this case, we carried out
these similar experiments

using clothing very similar to what
Rachel was wearing on the day.

It's a very common part
of forensic science,

allowing us to focus
our tests properly.

Particularly interesting here

was the fact that her clothing
had been disturbed,

some of it had been pushed up

and some of it
had been pushed up down

because it looked as though this had
been a sexually motivated assault.

That was quite clear
right from the very beginning.

Ancl whoever had committed
the crime...

...might have left some of
their own DNA behind on it

while they were doing this.

So it was really important to see
whether we could find any of that.

The area specifically in this case

was around the button area
on the jeans

and the waistband of jeans.

Unfortunately,
we didn't obtain any DNA profiling

that wasn't different
to Rachel herself.

And so, we were unable to obtain
DNA profiles from that.

As the search of the clothes
had failed,

Andrew McDonald took one last chance

to look for more of
the killer's DNA.

He went back to the tapings
from Rachel's body.

These had revealed a mixed profile
from Rachel and a man

who was almost certain
to be the killer.

But the tapings were running out.

Andrew knew that any mistake now
would mean that the evidence

of who killed Rachel
would be lost forever.

There's pressure on you
as a scientist

because there's a limited amount
of material to work with,

and you want to make sure
that you have clone your very best

to obtain the most
informative information you can

out of what might be very limited
and very precious material.

We had to think long and hard about
what we could do.

For more than two years,

Andy and his team worked to develop
a new process

which would allow the search for DNA
on the tapings to continue.

We had to spend a long time
testing this new technique

on all sorts of samples,

just to make sure that this process
actually worked,

until we came to a point
where we had confidence

that there was a good chance

that we could now do something
with this mixed profile

and see whether we could obtain
more from it than we had originally.

This new process purified
and concentrated

the remaining traces of DNA
to increase the amount

which could be analysed.

This ground-breaking work

was to become known
as DNA Enhancement,

and it was to be a game-changer.

We now had 12 components
in the minor portion of that profile

that was from some unknown source.

Ancl that gave us enough
of a DNA profile

to make meaningful comparisons

to people of interest
in the investigation.

This was the first time
the DNA enhancement technique

had been used in in case work,

and we were very relieved
and pleased

with the way it had worked.

Even with our amazing
new DNA profiling techniques

that we use now,
it's still very important,

but there
it was absolutely critical.

After two years' work on the DNA,

Angela's team
finally had a male profile.

So we'd come from this
with strange finding

of absolutely no DNA

to a position where we had not
only a full profile from Rachel,

but we also had enough DNA
forming part of a male profile

to be able to identify someone
from it.

So it was a huge... a huge advance.

Now detectives could ask Angela
and the team

to compare the partial DNA profile
they had identified,

with a list of suspects

who had carried out sex attacks
on women in the London area.

Ancl so, we went through
all the different people

that the police had
as people of interest,

and there was only a match
to one individual.

Everyone else was excluded.

And that match...

...was to a man called Robert Napper.

NARRATOR: World-leading forensic
scientist Dr Angela Gallop

and her team were on the hunt
for the killer of Rachel Nickell.

After two years
of painstaking DNA analysis,

their ground-breaking
new techniques

had finally delivered
a breakthrough.

They had obtained
a partial DNA profile of a man,

from tapings off Rachel's body.

This appeared to belong to someone

who was already on
the police database

of men who had committed
violent and sexual of fences.

So who was Robert Napper -
the new prime suspect?

Almost three years
before Rachel Nickell's murder,

there had been an horrific attack
on a young mother in her home

near another south London park,
Plumstead Common.

The attack sparked a major inquiry
by the Metropolitan Police.

There was a rape in a house
just off Plumstead Common...

...where a young woman was raped
in her own house.

Someone climbed in
through the back garden,

went upstairs, raped her upstairs

while her children
were having breakfast downstairs.

A DNA trace was left
at that and...

but there was no match
on the system,

which was in the early clays of DNA,
remember.

It transpired that
that person was Robert Napper.

He seemed to have

some sort of, erm...
remorse about it

because he confessed to his mother.

Ancl she went down to Plumstead
Police Station to report it.

Unfortunately, the person who looked
at the crime books at the time,

who has never been identified,
didn't find a record of the crime.

He could have been caught

at that very, very first
rape incident,

but he wasn't.

And from then on,

his mental state
deteriorated until by 1992,

he was attacking women regularly

in south east London

and became the Green Chain Rapist.

The Green Chain
is a linked series of country walks,

and parks and recreation areas

that span across several miles
of the south London suburbs,

and it's known colloquially as,
signposted as the Green Chain Walks.

From being a word which described

a beautiful, peaceful past time
to be doing

was suddenly linked
to a series of horrible rapes

that occurred
during the early part of 1992

within very short, sharp succession.

In at least two incidents,

the victims were young women
out walking with young children,

with toddlers or with babies
in pushchairs, buggies.

And it's extremely unusual,

vanishingly rare,

for rapists to strike and attack
a woman when a child is present.

It's psychologically, I think,
it's thought to be a deterrent.

There were dozens of attacks in all,
between 1989 and 1992,

with the Metropolitan Police

forced to put together
a special squad

to try to catch the rapist.

They had a DNA profile

from four of these rapes.

There were more, but from four,

we knew that they were all committed
by the same person.

That profile did not appear
on any police record.

Until that person
came into the remit of the police

and the DNA was taken,

they had no clue
as to who could be responsible

for the series of rapes.

Then, in November 1993,
this quiet residential street

near Plumstead Common
witnessed a crime

which shocked even the most
hardened detectives.

A murder occurred in Plumstead,
of Samantha and Jazmine Bisset...

...which were on the scale
of ferocity and horror...

...something which
I had never experienced before

as a murder investigator.

I had no idea
until I got to the scene

just what I was going to find.

It was a small ground floor flat,

and in the main living room
lay the body of Samantha.

Ancl she had been eviscerated,
basically.

All of her joints were cut.

She was cut wide open,

and her internal organs
had been stabbed.

Ancl then, of course,
in the in the bedroom

was the body of her
four-year-old daughter, Jazmine,

who had been, we subsequently found,

sexually assaulted too.

Detectives investigating
Rachel Nickell's death

ruled out any connection with
the murders of Samantha and Jazmine.

They already had Colin Stagg
in custody,

and, at the time,
he was awaiting trial.

But many felt
that the striking similarities

between the crimes
were too stark to be ignored.

Rachel was with her child.

Samantha Bisset has been murdered,

and her child has been murdered
at the same time.

There are elements contained
within both those murders

that are really, really unusual,
really stand out.

Really, you know, there won't be,
you know,

are there any other murders
like these

anywhere else in the country?

But, of course,
the response was coming back,

"Well, you know, they can't be
the same people involved

"because, you know, we've got
Colin Stagg in custody over Rachel,

"and he'd been in custody
when Samantha was murdered,

"so he can't have done it."

And I was saying, "You know,
this is... this is bizarre.

"There's something wrong here,

"there's something
that doesn't add up properly."

At first, it appeared
Samantha andjazmine's killer

had left no clues at the scene.

But the murder squad decided
to double check

every fingerprint found in the flat.

All of the fingerprints
were put through again.

Ancl lo and behold,
a fingerprint on the balcony

and the fingerprint on the cot
ofjazmine

were not, as has had
originally been supposed,

the fingerprints of Samantha Bisset.

They were belonging to
one Robert Clive Napper.

Napper's fingerprints put him
at the scene of the Bisset murder.

On arrest, his DNA was taken,

and it was found to match the DNA

left at several of the scenes
by the Green Chain Rapist.

In 1995, Napper was convicted
of Samantha andjazmine's murders,

a rape and two attempted rapes.

And fairly quickly
after the court proceedings,

he was accepted into
the psychiatric care system,

and he became an inmate

at the very famous secure
psychiatric hospital at Broadmoor.

The tragedy of this case,
of course,

is that there were opportunities
to identify Napper.

But unfortunately,
he was able to go on,

and tragically,
murder Samantha and Jazmine.

But with Angela Gallop's
new DNA discovery,

the crucial question now was:

Had Napper, a convicted murderer
and rapist,

also killed Rachel Nickell?

The first results obtained by
Angela's team seemed to suggest so.

But the result was not conclusive.

We had Robert Napper
as the only man

who could be responsible
for the DNA that we had detected.

But we had to be very mindful

that all we had in the DNA profile
was 12 components,

which is quite a lot,

but it's not a full DNA profile
by any means.

So we needed to explore further
if there was any other evidence

to suggest that Robert Napper
was responsible for this of fence.

To further explore
the DNA connection to Napper,

Andrew McDonald analysed

the part of the sample
from Rachel's body

which could only have come from
a male.

Males and females
have different sex chromosomes

within their bodies.

A female will have two X chromosomes

and a male will have
an X and Y chromosome.

So because females
don't have a Y chromosome,

if we can target DNA
only on the Y chromosome,

therefore we can analyse DNA
that is only male in origin,

even if you've got a large
background of female DNA present.

Ancl we were able to get an almost
full profile from that sample,

that also matched Robert Napper.

By targeting the male chromosome,

Andrew McDonald had obtained

an almost perfect DNA match
with the prime suspect.

But were there other exhibits
hiding more forensic secrets?

So now we had DNA,

which was an extremely strong link
with Robert Napper,

so we were obviously wanting to
look at Robert Napper himself

and see whether any other types
of links that we could get

that would support the DNA evidence.

In Napper's flat on his arrest,

there were various items
which pointed to his guilt.

There were weapons of of fence,

daggers, which were made just
to cause injury and kill people.

There were ropes.

There were books on martial arts
and vulnerable parts of the body.

Some of these items were kept
in a red metal toolbox.

He seemed to be a little bit twitchy
about this toolbox

and liked to know where it was
and keep it close to him.

It soon turned out the toolbox
held an amazing secret.

A forensic trail

which would see
Rachel's young son Alex

help solve the murder of his mother.

NARRATOR: It is 2004.

Dr Angela Gallop and her team
have found DNA evidence

to suggest Robert Napper
murdered Rachel Nickell

as she walked with her son
on Wimbledon Common.

But they need more evidence.

Angela and her lead examiner,
April Robson,

came together to discuss
which of Napper's possessions

might reveal a link
to the crime scene.

They began to hone in one item -

Robert Napper's toolbox.

He was always a little bit twitchy
about his toolbox

and, you know, was keen on
having it... Bit possessive.

Yes, on having it close to him.

Napper's concern about
his red toolbox was a giveaway.

It was to provide an astonishing
forensic link to the murder.

So, we asked to see the toolbox.

Ancl when they submitted it,

we discovered that
it was a steel toolbox

painted with a thin layer
of red paint over the top.

Ancl this was interesting to us
because April,

in this way she has
of looking at things

and remembering things she's seen

and then later on connecting it
with other things,

she remembered that she'd seen

a flake of red paint
in the hair combings

taken from Rachel's son's hair.

Hair combings had been taken
from Alex at the hospital

on the request of
the first detective at the scene.

Hair combings are to be considered

because people get grabbed
by the hair,

or in a struggle,

things can be passed on
and get tangled up in the hair.

And Mex, the son of Rachel

was the only eyewitness.

So dealing with him was important.

As important as his mother in terms
of forensic recovery on his person.

The hair combings came in,

and it was a folded piece
of white paper and a black comb,

and there was very little debris
there.

We thought we might find
some vegetation or maybe some,

you know, clues from
the actual location.

However, when I looked at them
under the microscope,

there were some red fragments.

And at that time, it wasn't
very obvious what they were.

They were very brittle,
they were single-layered,

but they had like
a grey silver back to them.

So for me, it just looked like
quite brittle red paint.

April had logged this discovery
of red paint in Alex's hair

early in the re-investigation.

It always stayed in her memory.

Whenever you have a circumstance
like that, you always think,

"Oh, we'll just have a quick check
with the paint from the toolbox."

Ancl so, this was the moment,
I think,

that Mike was introduced properly
into the team

and compared the flake
from the hair combings

with the paint on the tool case.

There was a similarity,
microscopically,

between the red paint flecks.

There was also a similarity
chemically between them,

There were also some metal flecks

that were attached
to some of the paint,

and we did another type of
elemental technique

to show that those metal flecks
were a type of steel

and were similar to the steel
that had come from the toolbox.

That established beyond doubt

that those paint flakes
were the same.

Robert Napper had probably kept
the murder weapon in the toolbox.

On the day of the murder,
he'd opened the toolbox.

In doing so, infinitesimal pieces
of paint had come off,

had flaked off that toolbox,
got onto his clothing.

And at the murder scene,
some of that red paint

was transferred
from Napper's clothing

on to Alex's head.

And that was sufficient to prove
that he had been there that day,

and he had to be the person
that murdered Rachel.

So that was our second piece
of evidence in the case.

But the toolbox
was not the only item of Napper's

which police had brought
to Angela's team for examination.

One of the things that was noticed
at the time

was the fact that there were
some shoe marks made in a muddy area

right by the crime scene.

There were witnesses to a man
washing his hands in the stream

near to where Rachel
had been murdered.

Shoe prints were taken
from that scene.

Criminals, when they walk into
a crime scene,

they're not thinking about leaving
their footprints behind.

They're wearing gloves
to keep fingerprints away.

They're not thinking about
their footwear impressions.

I had some casts that were taken
from the crime scene back in 1992,

and I was asked to compare that
to a pair of dress shoes

that were attributed to
Robert Napper.

By looking at the sole of the shoes
that we were presented with,

we discovered
there was one heel mark,

which looked very much like the heel
of one of these shoes.

What I originally found on the cast
was this small lattice pattern

that had been replicated

from the crime scene impression
to the cast.

And I also noticed what appeared
to be a small lattice pattern

on the heel of one of the shoes
that I had gotten for comparison.

But the only problem with it
was that the cast of the mark

was just slightly smaller
than the heel itself.

Ancl in forensic science,

if there's a difference between
two things that you're comparing,

if you've got something

and you've got a potential source
for it

and they're not exactly the same,

the same dimensions
or the same type of thing

or same microscopic appearance,
whatever it might be,

then you have to say that there
couldn't be a link between them.

But in this case, it seemed to be
worth pursuing a bit.

One of the ways of answering
that question

as to why I have a size difference
between the cast

and the heel of one of the shoes
was to try and do a reconstruction.

We had a similar pair
of dress shoes,

and I had one of my colleagues
put on those shoes

and walk through the path,
that muddy path.

And then what we did is,
we cast a representative amount

of those impressions.

And brought them back to the lab
for analysis.

Ancl he discovered that what happens

as you withdraw your foot
from the mud,

that the mud closes in slightly,

there's a sort of partial
vacuum created.

Ancl as you withdraw
the shoe from the mud,

it's closed in a little bit.

So then when you make a cast
of a mark like that,

it will be the cast is slightly
smaller than the shoe itself.

Ancl so, that would explain
absolutely why the cast

didn't quite match the shoe
that Robert Napper had,

but it certainly would have done
in that sort of muddy ground.

That puts him standing by Rachel.

It's irrefutable.

Good as a fingerprint.

That was the third type of link
that we had with Robert Napper.

More than a decade after the murder,

a tiny patch of Wimbledon Common

had revealed three key pieces
of evidence.

And after four years
of intense forensic reinvestigation,

Angela and her team
finally had enough evidence

to link Robert Napper
to the killing of Rachel Nickell.

The more evidence you get
linking someone with a crime,

the more confident that you can be
that you have a really good case,

forensic case to present at court.

So I think it was good
to get the DNA profiling link.

But then when we went on
and we were able to improve on that,

with such diverse things
as red paint and the footwear mark,

then it just gives you confidence.

Ancl so when Robert Napper
pleaded guilty to the crime,

you think, "Yeah".

It's a good feeling, that.

In December 2008 -

16 years after Rachel was killed -

Robert Napper pleaded guilty
to her manslaughter

on the grounds
of diminished responsibility.

Already in Broadmoor Hospital

for the murder of
Samantha and Jazmine Bisset,

it was ordered
that he should never be released.

The police could not have been able

to satisfactorily conclude
this case, you know,

without the work of people
like Angela Gallop.

I mean, I think we should all
take our hats off to her.

She did a fantastic job.

I cannot put enough stress
on the importance

of good forensic investigation.

I go so far as to say
that without the forensic input,

the murder of Rachel Nickell
would never have been solved.

Mr Napper has been found guilty
of Rachel's murder.

That means in total,

he's murdered two women, one child,

raped at least one woman

and attempted to rape two others.

We sincerely hope,
whatever the court says,

that he will spend
the rest of his life

in a totally secure environment
to protect all other people.

That terrible summer's day
on Wimbledon Common

changed the life of Rachel's son,
Alex.

But he has found the strength
to cope...

and to forgive Robert Napper.

It's about understanding
that forgiveness is for yourself.

You know, you forgive other people

when you go through situations
like this for yourself,

so you can let go
of that negativity, you know.

Ultimately, the way we choose
to feel about situations

once we've lived through
difficult situations,

that's a choice that we make.

So I think we have to
make that choice ultimately

and make that transformation.

Rachel had been out walking
with her young son,

a perfectly normal, natural,
everyday activity.

Ancl I think that's what made
the attack on her

all the more horrific in a way,

the contrast between normality
and what happened to her.

There was satisfaction in knowing

that someone who committed
this absolutely horrendous crime,

he had been identified
and justice had been clone...

...insofar as it ever could be
for Rachel and her family.

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