Original subtitles

When a murder is left unsolved...

No weapons, no eyewitnesses, no forensic evidence at all.

There was nothing.

..And a killer is on the loose...

These people are still out there. Who's going to be next?

..Britain's cold case detectives will never give up.

The best way to solve a cold case is to keep it warm.

No matter how long it takes...

This case dominated my life.

..They'll investigate every angle and uncover every clue...

Searching through thousands of people.

They think they've got away with it. They haven't.

..Until the killer is caught at last.

We all leave a trace.

We'd finally identified that golden nugget. Bingo, we've got him.

Edinburgh.

On the evening of October the 15th, 1977,

two 17-year-old girls went missing without a trace.

It began an epic investigation into a case

that would shock the whole country.

Tom wood was a young detective sergeant at the time.

When I came into the office the place was already buzzing.

There were people in the office

that shouldn't have been there on a Sunday afternoon,

there were senior officers all over the place and there was a real

feeling that we were dealing with something that was different here.

Best friends Helen Scott and Christine eadie

had gone for a night out in the city, but hadn't made it home.

Helen's brother, Kevin, was 11-years-old at the time.

The household was a bit frantic.

My mother and father were both making phone calls

to Christine's friends and any contacts that they had

to try and find out if maybe Helen had stayed the night somewhere

with one of her friends.

Helen would not have not come home unless she couldn't.

Helen and Christine were reported missing by their parents

on the morning of Sunday the 16th of October.

And that of course immediately raised alarm bells.

Two young girls, 17-years-old, just left school.

We didn't see them as being young women as much as being children.

They had just started work, just got their first wages

and of course the first thing you do

is you go and you buy something special.

And Helen had gone out and bought this expensive burberry coat,

which was her pride and joy and which she wore for evenings out.

Before police launched a search,

a call came in from a member of the public.

Late in the morning of Sunday the 16th of October,

a couple were walking their dog along aberlady bay

in east lothian near gosford, about 20 miles from Edinburgh.

And as they walked along they saw the body of a young woman.

It turned out to be Christine.

She was lying on her back, hands tied behind her back,

feet bound and gagged and obviously dead.

The radio was on in the kitchen and the news came on

and at that point we heard a body had been found

on the beach in gosford bay.

There was a sort of silence

and I think you could see the worry on...

..Everyone's face.

As detectives secured the crime scene

and searched the area for evidence, Tom's office received another call.

This one from a farm six miles up the road.

At that time it was Autumn

and it was much, much colder and bleaker here.

It was just here that the farmer saw something

lying in the middle of the field, just over to the right here.

He thought at first it was somebody who had dumped some rubbish,

but when he got there he found it was the body of a young woman

lying on her coat, her outstretched coat,

still wearing her burberry coat, bound and gagged.

So we were pretty sure right from the start,

before we actually saw it, that this was the body of Helen Scott.

There was a knock on the door and it was the police.

They had a bag with them.

And in that bag was some of Helen's belongings.

And at that point we knew that...

..Helen had been murdered.

My mother...

..Broke down in tears.

My father very much held it together,

but you could tell he was struggling.

Police immediately began a murder investigation.

One that would take almost four decades of dogged detective work,

make history and change Scottish criminal law.

This case I suppose, from a personal point of view,

because I lived with it for most of my service

and because I ended up leading it,

I suppose was the most important case that I've ever dealt with.

But at the end of the day, if you ask what difference did you make?

Erm...

Well, we made a difference.

We made a difference with this investigation.

Like any murder investigation,

it began with an examination of the crime scene.

Both girls had been bound and gagged,

then strangled with items of their own clothing.

The postmortem showed they had also been raped.

Two young girls and they were barely more than children,

they were 17-years-old,

who had been abducted and murdered in the most brutal fashion

right in the middle of our city.

This was something different.

This was cold and callous.

It was a real turning point, it was a landmark case,

it was almost like the death of innocence within Edinburgh.

The way the girls' bodies had been dumped was, for Tom wood,

a clue to the type of killer they were dealing with.

Just about a quarter of the way up is where Christine's body was found

and you can see somebody stopping there at night

would have a very good sightline.

They would have been able to see any car lights coming.

It appeared to us that this was somebody

that had either done this before,

or had thought through exactly what they were going to do.

It was an organised crime scene.

There was nothing chaotic about it.

Dr keri Nixon has 20 years' experience of working with the police,

dealing with some of britain's most disturbed criminals

and has studied this case in detail.

What we know from research

is that offenders who are very mentally disordered

will often have crime scenes that mimic that.

So the crime scene will be very disordered and chaotic.

So when we see a crime scene like this that is quite organised,

we can see straight away that it's not an offender

that's in some kind of psychotic episode.

They are treating their victim as an object,

an object to be used for their own pleasure.

That suggests he's a sadistic and sexually motivated predator.

And in most cases,

this type of murderer is a stranger to their victims.

The last thing you want in a homicide investigation is a stranger murder.

Most people are murdered by people they know

or people they have a connection with.

That gives you a head start.

But two random, motiveless murders

weren't the only challenges Tom's investigation faced.

Forensic evidence and forensic examination

was very different then, obviously, to what it is now.

DNA was still unknown at that time in terms of an investigative tool.

But if these girls had been killed by strangers

and with their bodies being left outside,

it was always going to be an uphill struggle.

Two bodies were found out in east lothian,

yet there was no quick arrest.

I think that would have given a huge sense of frustration.

Someone must know who they are, but it's not led to anything

and that must have been very difficult for people to take at the time,

that something as horrific as this had happened

and they might have been wondering, who is going to be next?

In 1977, two 17-year-old girls, Helen Scott and Christine eadie,

had been found raped, murdered and dumped just outside Edinburgh.

The killings were random and sexually motivated,

meaning ds Tom wood and his team faced an enormous challenge,

whilst the citizens of Edinburgh lived in fear.

Obviously there had been murders in Edinburgh,

but the fact that this was two young women

who had gone on a night out and never came home,

that is something that would have been a huge shock to people.

With the city reeling,

Tom's team frantically rounded up the usual suspects.

We instantly started looking for people we knew

who had convictions for serious sexual crime.

You had to what we call tie, or trace, interview, eliminate.

Where were they? Who was with them? Who can alibi them?

Well, it was very, very difficult,

especially remembering that all of this was being done

on a card index system.

Tens of thousands of cards with information, all filed.

The error factor was enormous.

Tom and his hundred strong team

struggled under the weight of paperwork.

And detectives at the scene were beginning to understand

the type of killer they were dealing with.

The crime scenes were highly organised in that nothing

that wasn't the girls' had been left at the crime scene.

There were no foreign objects left.

But the way Helen and Christine had been bound

left one significant clue.

One of the girls was tied with reef knots

and the other tied with granny knots.

Now that's important in that people instinctively

tie knots in a certain way.

So this was evidence, we thought, that two men had been involved.

And because Helen and Christine were very fit, strong young women.

One man could not have overcome the two girls.

Tom and his team were confident they were looking for two men,

but needed witnesses.

So they turned to the bar where the girls were last seen.

At about 9:30pm they got to the world's end pub.

In the process they had met up with various pals.

Now, both the girls had had a drink but were not drunk.

So they were all in the world's end pub chatting away

when their friends noticed two strangers to the company.

Two young men who they did not know, but who were in the pub,

were engaged in conversations with Helen and Christine.

The descriptions of the men were quite interesting

in that they were not locals, they had not been seen before.

And they had short hair.

Now, 1977 was the time of long hair and the droopy moustaches

and all the rest of it.

So these guys were strangers.

So these women were seen leaving the pub with two men.

They were seen disappearing off into the night.

And what we think happened was that the two men offered them a lift.

And that was the last time they were seen alive.

The two male suspects made the pub central to the investigation.

Now, the world's end pub was an inquiry within an inquiry,

an investigation within an investigation.

It was one of these sort of stopping off places

where people popped in for a pint.

So we had to try and trace everybody

who had been in the world's end pub that night.

For detectives back in 1977, that was a huge challenge.

It was the dark ages.

There was no cctv.

There was no mobile phone information.

We couldn't even determine who had phoned,

who had used the telephone, the pay telephone, in the pub.

We had none of that.

The pressure was on to close the case because the fear was

if these killers weren't stopped they would strike again.

The thing that we need to understand about sexually motivated offenders

is that they are driven by a need, a compulsion,

to control somebody sexually.

And when they offend that relieves that tension, that anxiety,

for a period of time.

But then it builds again

and they need to do it again and again and again.

Tom's team began the painstaking work

of tracking down everyone who was in the world's end that night,

as Helen and Christine's horrific murders

were gaining huge nationwide media interest.

It was certainly covered quite extensively

on television news at the time, newspapers,

there were billboards about it.

This was an unsolved double murder

and there didn't appear to the public at least

to be any significant leads that they knew about.

It was very, very difficult at times because there would be days

when I would just go into a shop

and just see a picture of my sister's face

on the front page of a newspaper and you wouldn't be aware.

The city of Edinburgh and the nation were gripped.

It was a mystery, a genuine mystery.

These two women had gone out, something had happened to them

and then their bodies had been found.

Who had done it? Was that person still out there?

In the days following Christine and Helen's murders,

their families had to come to terms with the terrible reality

that they weren't coming home.

There would be good days, bad days...

..Days to think,

days to cry, grieve.

What happened to Helen, it changed all our lives.

I remember the first Christmas after Helen's death.

I'm an 11-year-old and the last thing my parents wanted was Christmas,

but do you know what, they were going to do Christmas for me

and I was going to do Christmas for them.

And even on that Christmas,

Helen had, with her first wages, started her Christmas shopping,

so...

So even I had a Christmas present from Helen

the Christmas that she wasn't with us, the first Christmas.

Six months after the murders of Helen and Christine

there was still a huge amount of publicity,

generating hundreds of leads for police.

People started phoning up and saying,

"I think it was Freddie next door or I think it was my ex-husband,

"I think it was my ex-boyfriend."

But you've got to go through the process of eliminating all these people.

So it was a massive, massive inquiry.

Tom's team of detectives had interviewed 500 possible suspects

and taken thousands of witness statements.

But one year after the murders of the two girls,

police were no closer to making an arrest.

Witnesses gave descriptions of those men.

Photofits were produced.

Yet, there was no quick arrest.

For the public in Edinburgh at that time,

just that sense of these people are still out there,

that must have been huge for them.

The world's end murder investigation had hit a brick wall

and police had a difficult decision to make.

You cannot carry on with a team, a squad of 100 detectives,

investigating nothing.

What you've got to do is you've got to scale it back

and make sure that you are alert and in a good position

to take advantage when new relevant information comes.

And that's what we did.

When the decision was taken to scale back the investigation,

we just had to accept it.

The roads and the routes that they went down,

they were often just dead ends.

And the investigation just tailed off.

Sadly, we thought that this person would strike again,

or these people would strike again.

And no-one would wish that on anyone.

But everything was pointing to these killers murdering again

and it wasn't looking like the police

were going to catch them any time soon.

The hope though was that one day forensic science would.

Helen's coat was really the only main piece of clothing

ever recovered and she was found lying on it.

And shortly after we took it back to the lab

we discovered that there was a large stain on the coat.

Now, what we could do at that time

was we could test positive for semen, which we did,

and we got a positive for semen.

But that's about all we could do at that time.

Very fortunately for us at that time,

we had a very good crime scene management set-up.

Forensic scientists actually attended the scene of crime.

Now, that's standard now but it wasn't standard then.

A very young biologist, he was only 23 at the time, Lester knibb,

took ownership of this crime scene.

Lester knibb and his colleagues had a belief

that as forensic science marched on,

eventually this coat would give up its secrets.

So I've always described it

as being like in possession of a rosetta stone

where there is a coded language which you cannot understand,

but one day you'll be able to decipher it

and it will give up its secrets.

The investigation may have been cut back,

but Christine and Helen were never far from Tom's mind.

Many police officers have full careers

and are never involved in cases as important as this.

This wasn't only the most important case for me,

it was the most important case for many officers who investigated it.

Allan Jones joined the police straight out of school in 1979

and was drawn into the investigation immediately.

The world's end was really significant for me.

I was more or less a contemporary of the girls as well.

I was born in '62, they were born in '60.

So I was aware of the press and media attention

that related to the murders and the aftermath.

And I had the privilege, because I was a cadet

and you were going to get experience in different departments,

one of the departments I visited was the cid.

And officers were still working on the case.

So as a 16-year-old,

you are mesmerised by the complexity of something.

There were thousands of cards for every person that was interviewed.

Walls of statements.

And still some ongoing enquiries.

It was a massive part of my career.

Some of the greatest highs and lowest lows

happened during the course of it.

In 1998, over 20 years after Helen and Christine's murders,

the scientific breakthrough Tom wood had hoped for finally happened.

And it looked like the secrets of the stain on Helen's coat

might be unlocked at last.

They came and told me, "we've got a DNA profile.

"We've nothing better to do now

"than match it against the DNA database,

"which was growing at that time, and we'll find a match

"because this person whose profile we've got,

"we must know who he is

"because he must have offended before or offended since."

That was our belief. And I remember thinking, we've done it.

In 1998, 21 years after the murders of Helen Scott

and Christine eadie, forensic scientists made a breakthrough

when they managed to retrieve a DNA profile

from the stain on Helen's coat.

The national DNA database held samples

from every criminal arrested since it was set up in 1996.

Tom was certain it would deliver a name and the case would be solved.

We took this profile and we checked it against databases

and got nothing.

It was a huge disappointment

because we were so convinced we had the answers here.

So we checked it against the database here,

we checked it against the growing databases in Europe

and Australia and the United States, the FBI database.

Nothing.

It was a bitter blow, but Tom refused to give up on his quest

to get justice for Helen and Christine.

He sent a team, including Allan Jones,

to get samples from every known suspect

from the original 1977 investigation.

273 people were in the pub that night.

And we had the names of every one of those.

Some had passed since then.

But there was still a fair proportion in and around

and we tracked down all of the males.

And everyone of them, we went internationally, we went abroad,

we got offices abroad to take swabs to eliminate people.

After collecting a mass of samples, none matched the DNA from the coat.

Once again, the case looked like it had run cold.

It was a devastating blow to all of us.

Despite another setback detectives kept the case warm,

even making an appeal on the BBC's crimewatch in 2003.

Tonight, there's a chance of cracking one of Scotland's

most notorious double murders in modern history.

The killing of two teenage girls in Edinburgh back in 1977.

130 new witnesses came forward but still there was no progress.

Forensic science was developing faster than ever though.

Allan Jones' new job was finding advances to help catch

Helen and Christine's brutal killers.

I spoke with Tom wood about the way to take that forward.

We got all the experts in, behavioural advisers,

forensic experts from the forensic science service.

Everybody at the top of their game.

So they were able to feed in to me what's the best option

of getting a more definitive DNA result

or point us in the direction of whoever the suspect

or suspects were at that time.

Then in 2004, Tom and Allan had a breakthrough.

Finally, a small private company

said that the would deploy a completely new technique

to try and separate the different alleles of DNA.

It was like having a pot of broth

and picking out individual ingredients from the soup.

I mean, it was incredibly complicated, but they did it.

Allan was the first to hear the news.

The lead scientist at the time phoned me one Friday afternoon

and said, "I've got some news for you.

"We've examined that sample and there's two DNA profiles on it."

The discovery confirmed Tom's hunch that there had been two killers.

But was this newly discovered profile in the system?

We had two men's DNA there,

plus the DNA of Helen,

and of course it was her coat.

It had another complete profile,

and when we checked that against the database,

bingo, we got a hit.

It was Angus robertson sinclair.

Just as Tom had suspected,

Christine and Helen's murders weren't a one-off.

Glaswegian Angus sinclair was serving two life sentences

for his second murder and raping 11 underage girls.

The penny drops.

He's never been involved in the world's end enquiry,

not even on any of the suspects lists.

We had one of the two men identified.

Well, at that time, we'd been looking for him

for eight years, searching through hundreds,

if not thousands, of people, and then it was there.

The answer was there in front of us.

So, this is a guy who was considered so dangerous

that when he was jailed for life in 1982,

it was one of the few instances in Scotland where,

at the point he was sent to prison,

it was acknowledged that he'll probably never be released.

The profile was a billion to one match.

And after 27 years,

Tom and Allan finally felt they had one of the killers.

It was just a celebration.

Everything had come together and we'd got it.

We'd got... finally got one of the people who'd been involved

in these horrendous murders.

We were ecstatic.

Ecstatic.

But it was the start.

It was start of a long,

long journey to get to the place where we could finally convict him.

Tom and Allan wasted no time visiting sinclair.

We interviewed him in prison...

Are you able to recollect at all where you might have been

at that period in October 1977?

..And he gave absolutely nothing away.

Nothing.

I take it by that you're not wanting to respond to that question

asking you where you might have been in October 1977.

You can apply techniques to try and get them to break,

but in terms of someone like sinclair,

he was a hardened criminal, he would be set in his mind that,

during that interview, he wasn't going to be saying anything.

You're not wanting to respond to that question.

Is that correct?

Allan now turned to the other unknown DNA profile.

He looked at known associates of sinclair's from the 1970s...

..And quickly identified his brother-in-law,

former decorator Gordon Hamilton, as the most likely suspect.

Gordon was born in '55,

so he was Angus sinclair's junior by ten years,

but he'd died in 1996.

The reason he wasn't on the DNA database is he has no convictions

at all and was unknown whatsoever to the police.

He was an alcoholic.

He'd died destitute.

He had been cremated.

He had no histological samples, no hospital samples, no...

All of his possessions had been lost over the passage of time.

He had no kids.

So we could never... We could never get his DNA.

After coming so far, Allan was determined

no-one was going to get away with the girls' murders.

There was one option that we had to pursue,

and that was to try and find out residues that he'd maybe left

either on photographs or in buildings that he had been in.

It was a long shot, but Allan's team discovered a house in Glasgow

that Hamilton had decorated just before his death.

We went in 2005, myself and some other colleagues,

our forensic scientist took samples of the paper

and also some cornicing, some polystyrene cornicing,

and sent the materials down to the forensic science service again.

And lo and behold, on the inside of the cornicing,

where you would place the two corners together,

there was fingerprints and DNA left within there,

and that DNA was Gordon Hamilton's,

and that DNA was the exact same DNA that we'd been looking for

for all the years since 1996.

The police were confident they had finally found

both Christine and Helen's killers.

They then spent a year and a half

building the case against Angus sinclair.

There was a whole lot of supporting evidence that went with this case.

Think of it...

The DNA on the... On the coat was the strong central pillar.

Like the main tent pole of a tent.

And the other supporting evidence was all the strings

that went round to support that pole.

That was how the case was.

The trial of Angus sinclair began on the 27th of August, 2007.

30 years after Helen and Christine's murders.

This was a huge prosecution.

This crime that had gone unsolved so long was finally going to trial,

and there was finally the chance to convict someone for it.

Kevin was present in court.

The first time I saw Angus sinclair...

..I think I was quite surprised.

He was quite a small...

Quite a small man. He wasn't tall.

I think at the time you could tell he was probably quite a strong man.

Sort of stocky.

But...

..He just didn't look anything... Anything special.

People saw it as a piece of business that was finished.

People saw it as very important because, as I say,

the world's end case had sort of gone into the fabric of the area.

To the people of Edinburgh, a guilty verdict was a foregone conclusion.

But in a surprise move, the prosecution decided

to base their case on only one key piece of evidence.

The crown decided that they were...

..Going to go exclusively for the DNA evidence

on the intimate samples.

You know, the rape aspect of it

and the... The semen on the clothing etc.

The prosecution were confident it was enough to win.

But sinclair's defence destroyed their case.

He claimed he'd had consensual sex with Helen,

and his dead brother-in-law Gordon Hamilton

must have murdered both 17-year-olds.

Watching the case being badly managed in 2007

was like watching a train crash in slow motion.

There was nothing you could do about it,

but you knew what was going to happen.

On the 10th of September, 2007,

the judge acquitted sinclair of all charges due to a lack of evidence.

The prosecution's decision had been disastrous.

The case was abandoned at that time, and there was a furore.

Because it had been appearing in the press, it was an iconic case.

The fact that the case failed in court

was something that was felt by the whole of the community,

government, police, the law authorities themselves.

It was a shock.

And that shock, you know,

continued to go throughout society.

Everyone knew a guilty man had been let off the hook.

And despite the fact sinclair was just going back to prison for

the rest of his life anyway, he was incapable of showing any compassion.

It's a true narcissist's behaviour.

There's no reason whatsoever why this man couldn't have just said,

"yes, I did it,"

to save the families all that heartache.

He was enjoying it.

It was him being in control again.

In his offending, he liked to control.

And even when he was in prison, he still liked to control.

The result was devastating for everyone involved.

For me, we'd built up, then just dropped like stones.

And, erm...

..It was difficult. It was really, really difficult.

The double jeopardy law in Scotland meant sinclair

could never be tried for Helen and Christine's murders again.

Even if he confessed.

But many refused to accept that this was the end of the road.

It created a groundswell of feeling at that time

that this was a wrong that had to be righted.

It was just something that, you know, couldn't be allowed to happen.

It was a devastating blow.

We tend to think of miscarriages of justice

only in terms of people who have been convicted wrongly,

but miscarriages of justice can work both ways.

But this was wrong.

30 years after the tragic murders of Helen Scott and Christine eadie,

the trial of the man detectives were convinced was guilty,

Angus sinclair, dramatically collapsed.

And to make matters worse,

the double jeopardy law meant he could never be tried again.

You think, "it can't be.

"We've come this far, it cannot be the end of the road."

We firmly believed that Angus sinclair was guilty of this crime.

Public outcry over the case prompted the Scottish judiciary system

to review the law.

What it ignored was the fact that forensic science

was developing so quickly

that in serious cases, erm,

I may be found not guilty or no case to answer this... Today,

but in six months' time, there might be compelling forensic evidence

emerge to point me as absolutely guilty.

And this was particularly true of DNA.

Then, in 2011, the world's end murders literally changed the law.

Double jeopardy was repealed in Scotland.

Now anyone acquitted of a crime could be retried,

as long as there was new and compelling evidence.

That just absolutely meant the world to us.

It gave us the potential opportunity

to then get back in court...

..And...

..See justice done for Helen and Christine.

But before that could happen,

yet another advance in forensic science was going to be needed.

Allan Jones was the obvious choice to hunt it down.

I believe in chance, but this was really unusual.

After it had been repealed,

I was at a sio - a senior investigating officer's - conference

down in england,

and happened to come across the cellmark stand.

Where they were talking about new technology

they had introduced called sperm elution.

It's a more defined process to pick out organic elements within DNA.

It's much, much more precise and refined

than existing technologies had been.

And they were using that in combination

with a technique called crime light.

Allan took all the evidence to one of cellmark's senior scientists,

Geraldine Davidson.

This time, it was the carefully stored ligatures used to tie

the victims that proved to be crucial.

One of the really key things was that we had been able to see

photographs of how the ligatures were

for us to examine them.

And there were clearly still knots present

that had never been undone or examined previously.

So once you start thinking about the contact involved

in repeatedly tying ligatures,

you start having a reasonably high expectation

that whoever did that will have left DNA.

Crime light allowed Geraldine and her team

to use narrow wavelengths of light

to identify tiny particles of DNA deep inside the knots

that had previously been invisible.

So we were able to identify DNA that was matching Angus sinclair

and Gordon Hamilton.

It was exactly what Allen had been hoping to hear.

We knew it was there, we just needed time for technology to catch up

and provide the evidence.

And it did.

This new evidence proved that nothing had been consensual

about what happened that night in 1977.

It wasn't simply DNA by being touched...

..It was such that it could only have been caused

by him tying the knots tightly.

In other words, you know, it was not something accidental.

On the 13th of October, 2014,

37 years after the murders of Helen and Christine,

the second trial of Angus sinclair began.

I attended the trial.

He had a huge, long beard,

and he looked like a decrepit old individual.

And I don't know whether that was part of the plan.

There was a feeling that the acts of his past were catching up with him.

This time the prosecution's case went to plan.

I think, in contrast to the ultimate failure of the first trial,

the prosecution carefully led the jury through every point

of forensic DNA evidence.

They spelled it out very clearly, they had the scientists expressing

the possibility of things to, you know, being a billion in one chance.

It was really presenting a compelling picture for the jury

that there could be no other explanation for what happened

than sinclair being responsible.

On the 14th of November, 2014, the jury found sinclair guilty

of Christine eadie and Helen Scott's kidnap, rape, and murder.

When the guilty announcement was made,

I just put my head in my hands.

And it really felt like a...

Just there was a weight off my shoulders.

It felt like I'd taken a big heavy overcoat off.

Something that had been there for 37 years had just been lifted.

People have often said, "oh, you know, you must've been

"really delirious about it."

No, it was just an immense relief

that we had... the job had been done.

Yeah, that was an emotional day.

To be part of, you know, a historic change in the law

is just really satisfying.

A few days later, sinclair was sentenced to life

with the longest ever minimum term handed out by a Scottish court.

And one that was very symbolic.

So, the investigation had lasted 37 years,

and Angus sinclair was given 37 years imprisonment.

Having fought for justice for so long,

sadly Helen's father, morain Scott, passed away

just a year after the trial.

In a strange twist, he, erm...

..He died on October the 16th.

The same day as Helen.

Despite being convicted of four murders

and spending almost 50 years in prison,

police are still looking to connect sinclair

to other unsolved homicides.

Sinclair is known as Scotland's most prolific sexual serial killer.

But I think this is a man that is an absolute predator,

that there will be numerous victims that we know nothing about.

What I'm sure of is that Angus sinclair

was one of the most dangerous men

ever to walk the face of this country in the 20th century.

A cold case that was never closed,

the world's end murders have left a lasting legacy.

I was very proud of the way that the force I was part of

had at last delivered justice.

It had never given up, never stepped aside.

And that, because of the change of the law,

hopefully at some time some other victim will get justice

because of the legacy of Helen and Christine.

It's small comfort, but it's something.

A devoted mother disappears off the face of the earth...

I believed that she was never going to be seen again.

..And a technological breakthrough finally identifies her killer.

You will never get him.