Original subtitles

(dramatic music)

I'm David Wilson, emeritus professor of criminology.

And for over 30 years, I've investigated

the phenomenon of murder and what it is that might

motivate someone to kill.

Every murder case is different.

But time and again, a deadly pattern emerges

of warning signs and red flags.

In this new series, I investigate some of the UK's

most harrowing murder cases to understand how and why

these terrible crimes occur.

This is "Murder UK."

(suspenseful music)

In Berkshire, in the home counties, half-sisters Kylie Dembrey

and Tara Randall grow up inseparable.

(Tara Randall) She was very caring,

wanted to do everything for everyone.

She was very, like, cheeky, and she was gobby.

But there was nothing that we weren't used to.

Just sassy. (laughs)

(David Wilson) Kylie's mum met and married Tara's dad in 2000.

It was a bustling family home with five siblings.

The sisters could be a handful.

Kylie, in particular, was known for her energy.

She was funny, loving.

She could be naughty.

She used to wear my clothes.

(laughs)

She definitely didn't like school.

She used to go to the clubs, friends' parties and stuff.

But she wasn't bad.

(David) Tara naturally grows protective

of her younger sister, who suffers from epilepsy.

But as they enter their teenage years, Tara begins to mature.

And her interests shift to boys, and to one boy in particular -

Mark Sinclair.

(Tara) When I first met Mark, I was about 17.

Literally, I met him, and within, like,

I think it was, like, about three months, we were dating.

And he was just very kind, caring, just a nice, genuine bloke.

(David) Tara's relationship with Mark Sinclair

develops rapidly.

And as it does, she begins to see a disturbing change in him.

I fell pregnant with my first child at 17.

Then the drugs started, the drink.

He became nasty, like, real spiteful.

Wanted to cause an argument all the time.

(David) As Sinclair and Tara settle further

into teenage parenthood, his behaviour worsens.

When I had my eldest, the beginning was fine.

Then, when he was about three...

three months old, the drinking got worse.

I had to call the police because he'd left my house with my son.

If I refused to give him money for drugs or drink,

it would just cause a big uproar.

When I refused to give him money one night,

he literally threw me out of my bed with my son in my arms.

You could just see the rage in his eyes.

(David) Sinclair, who had been in care himself

from the age of 11, clearly struggles with parenthood.

Dr Donna Youngs has researched his mental health,

including the diagnosis of a serious personality disorder.

Dissocial personality disorder is...

it's almost like a low-level psychopathy.

It's one that was formed very early in life.

I mean, we're talking before the age of seven,

before the age of eight years old.

He rejects, he renounces all the normal social ways

of going about doing things.

He has a recklessness.

There's a callousness, a callous streak to him,

alongside, curiously, alongside a very passionate,

intense, loving streak.

(David) Former detective Paul Barton believes

Sinclair's diagnoses, when combined with his recreational drug use,

created a potent recipe for disaster.

(Paul Barton) Sinclair had been known to the police

since he was 17 years of age.

There are a number of people in this country

that have personality disorders.

Not all of them are managed by the police.

But I think this is particularly tricky when somebody

with a personality disorder is also addicted to substance abuse,

such as drugs or alcohol, because the effects that has

on those individuals is they become more volatile.

They become more paranoid, but also,

probably the medication that they're supposed to be taking

for their personality disorder is actually not working

because of the other substances they're taking.

He had quite an extensive criminal history,

which include a range of serious sexual assaults,

violence, threatening behaviour, and also weapon offences.

So he was quite a dangerous person.

(David) Mark Sinclair's psychology is, well, quite simply, alarming.

When you combine a diagnosis of anti-social personality disorder,

which would have a lack of empathy, a recklessness to it,

with chronic substance abuse, you've got somebody

who really does not know any social boundaries whatsoever.

And the drugs aren't creating that psychology.

What they're doing is stripping away

any last vestige he might have about social convention,

about rules, about boundaries.

And therefore, Tara's living with a very dangerous man indeed.

Initially bewitched and seduced by Sinclair's charm,

Tara doesn't know the man she's actually with.

She's unaware of his mental health diagnoses.

And she certainly doesn't know of his extensive contact

with the police prior to their relationship.

This included being charged at the age of 17

with sexual assault against a minor.

He was a completely different person,

completely different person.

He was... he was nasty.

Everything had to be his way.

And he was just evil, absolutely evil.

(David) Bearing witness to Sinclair's

increasing abuse of Tara, younger half-sister Kylie

often steps in to offer support.

(Tara) Kylie used to come and baby-sit the children for me

when we used to go out.

Obviously, some of it she was there for.

So she did see quite a lot.

(David) In 2008, having had two children with Tara,

Sinclair's drug use and his lifestyle choices

lead to a prison sentence.

And it's at this critical time that Social Services intervene.

They had done all their assessments.

And they... they basically said, because of the domestic violence

part of it, they would take my children for their own protection.

So basically, it was him or my children.

I chose my children.

I didn't want to be with him.

At that point in my life, I had got to the point where I'm like,

I actually don't want to be with you no more.

(David) Social Services knew their priority

was the children's permanent safety.

They had to assess the long-term risk Mark posed,

given his conviction for a violent offence.

Even with Mark behind bars, Tara was given a stark,

non-negotiable choice -

sever all ties to him now, or the children would be removed.

Tara is finally free from Sinclair

and his increasingly dangerous level of abuse.

But on his release from prison, a shocking secret is revealed.

Mark and Kylie had been seeing each other.

Mark and Kylie met when Kylie was baby-sitting

for Mark and Tara, Kylie's older sister,

which tells us Mark doesn't

subscribe to the normal social rules of behaviour.

(David) Sinclair dating Kylie, Tara's sister,

is simply another form of control.

It's the ultimate form of betrayal for Tara herself.

It further isolates her.

It further can degrade her own sense of self-worth.

And, of course, this goes back to Sinclair's underlying psychology.

This is somebody who can't empathise

with another person's feelings.

And so he must realise the impact on Tara when he starts dating Kylie

is to make her feel even more abandoned,

worthless, degraded.

(tense music)

(suspenseful music)

(David) What exactly does Kylie Dembrey see in Mark Sinclair?

I think it's that bad-boy-type image

because that's how he comes across, is a bad boy-type person.

The fact that Kylie, when she met Mark,

would have been very naive, very impressionable -

she was so young, 16 -

is a real factor in the way their relationship formed.

This relationship beginning in this clandestine way,

her being chosen above her sister in some ways.

And I think that all this excitement, all this drama,

and the charisma that I have no doubt Mark has

would have literally swept her off her feet.

(David) At the news of their relationship,

older sister Tara is immediately concerned.

I said to Kylie that, obviously, I didn't want the contact

because I didn't want him knowing anything about my children.

(David) But other family members are not worried.

Mum Theresa doesn't know about Sinclair's dark criminal past.

Kylie had been seeing him for a few months

before we actually met him.

He seemed kind.

He treated Kylie like a princess.

Obviously, he made her happy.

(David) In 2008, Kylie and Sinclair move in together.

I think the choice that she has made

has been a particularly unfortunate one

because he can be so deceptive.

Because this covering of attractive, charming,

charismatic qualities is just... is just that.

It is a facade beneath which this very different personality

also lingers.

They seemed like a really good couple together.

(David) But over the course of their early relationship,

Mum Theresa does begin to notice things, things of serious concern.

Used to come home, and she would have a bruise

or a mark on her body.

Obviously, when I used to ask her,

she would say things like she'd fallen over.

But she wouldn't tell us the truth.

I said to her, why do you want to be with someone who's controlling,

telling you, you can't wear this

and you can't wear that?

(David) Perhaps it's because, like Sinclair,

Kylie herself had been diagnosed with a personality disorder.

Hers, however, makes her prone to unstable relationships

and a deep worry that people might abandon her.

How does she know just how abnormal it is

for her to be in fear of violence from her partner?

How would she know?

She doesn't have that background experience.

What we have with Mark are two very distinct components

to his personality.

So we've got this intensely loving,

passionate, doting, romantic side of him,

and then this ever-present violent potential

waiting to be unleashed.

(David) Later in 2008, Kylie receives news

that intensifies her connection to Sinclair.

She's pregnant by him.

(Theresa) When Kylie first found out that she was pregnant,

she was like any mother.

She was excited.

She couldn't wait.

(David) The pregnancy, however, doesn't give any pause

to the abuse, though Kylie will often downplay,

rationalise, and contextualise it.

It's quite common in sort of longstanding domestic abuse

situations when the police get called,

and the perpetrator is arrested and then taken back into custody.

And then the victim has that kind of cooling off period,

that downtime to start thinking about the consequences.

And it's not uncommon for a victim of domestic abuse

to actually change their mind and say,

you know, I don't want to press charges.

(David) In September 2008, the authorities

do recognise Kylie as a victim.

Sinclair hurts her badly.

He's arrested and pleads guilty to battery.

This is the police's first official record

of contact with the couple, and they talk to Kylie.

(Paul) I don't think Kylie ever saw herself as a victim.

And I'm fairly confident Mark wouldn't have allowed her

to see herself as a victim.

(David) On release from custody,

Kylie allows him back into her life.

(Theresa Randall) He came out of prison

a month before baby was born.

(David) Their child's birth offers a moment of relief.

They seem to have put it all behind them.

We were all happy.

Mark was excited, cried.

And it was just a happy day.

(Paul) So you've got to remember that

Kylie was only around about 16 years of age

when she first met Mark.

So then to suddenly be in love and loved by an individual,

you know, and have a child with them has probably

had a massive impact on Kylie.

You know, she doesn't know any different.

And I think she really relies on Mark,

who's probably said, if I go to prison,

who's going to look after the kids?

Who's going to put food on the table?

We're talking about an emotional dependence,

where he had... he had a drug addiction, but she certainly had

an emotional dependence on him.

(David) By 2009, calls to the police about abuse at the house

Sinclair shares with Kylie come in thick and fast.

Her mum, Theresa, begins to see the physical evidence for herself.

(Theresa) He had no respect.

He used to smash my house, punch the doors.

It was scary.

You didn't know what to say to him.

He would go for you.

Because he's done it to me a few times.

(David) One of the questions that I think most people ask

in situations like this is, why does the person being abused

not get up and leave their abuser?

It's not as simple as that for a number of different

but interacting reasons.

The first is, after she has been abused,

there would then be an intense period

in which Sinclair would show her love.

And that relationship between what's healthy and what's abusive

becomes blurred.

And we know from decades of research about domestic violence

and coercive control that, ironically, the person being abused

is at greatest risk when she articulates the fact

that she is going to leave.

Now the risk is not just to Kylie but also to their young son.

And reports of domestic abuse and Mark's previous convictions

bring the couple urgently to the attention of Social Services.

(Paul) We know that the child was taken away

into care by Children's Services.

And that's an extremely serious step to take,

taking a child away from its mother.

But I can only assume that the Social Services and other partners

had considered the risk that Mark posed towards Kylie

and felt that was the only opportunity

they had to safeguard that child.

We've got to remember, the police have been called

on a number of occasions to this address,

where Kylie had refused to support a prosecution.

And therefore, you know, if she was making excuses

for Mark's behaviour, how could she

possibly safeguard her children?

It made me feel very angry, upset.

I couldn't believe it.

I'd lost my grandchild.

(David) As her one-year-old son is taken

into the protection of Children's Services,

Kylie, too, is devastated.

Despite the heartbreaking loss of her child,

Kylie still can't give up on Sinclair.

After the baby was taken away,

Mark and Kylie still stayed together.

(David) Even after Kylie loses access to her child,

when the child is taken into care,

that, ironically, must bring her closer to Sinclair

because she feels even more worthless,

she feels even more abandoned, and therefore,

will cling on to Sinclair in a way that

she hadn't previously clung on to

because it becomes more intensified.

She's bereaved, I would suggest.

She's feeling lonely, abandoned, and worthless.

(tense music)

And Sinclair's behaviour is becoming increasingly volatile.

He's arrested for violent offences and burglary

and spends time in and out of prison and mental health hospitals.

He always comes back to Kylie.

While Mark can be this callous, violent individual,

I have no doubt of his love for Kylie

and the way that they simply

couldn't stay away from each other,

and rings absolutely true to me.

There's a kind of till...

till-death-do-us-part quality to their initial relationship.

I mean, I think we even have Mark saying at some point,

if you try to leave me, I'll kill you,

just totally bringing together the two parts of his personality,

the passionate and the violent.

In that one sentence, you get Mark.

(David) By 2010, still living in Newbury,

their relationship is marred by periods

where, if Sinclair isn't in prison or hospital, he simply goes AWOL.

Kylie used to try and ring him.

Sometimes he would change his phone number.

The only time Kylie would ever hear from Mark

is if he would ring her.

But then Mark would just come back as like nothing had happened.

(tense music)

In the course of their 12-year relationship,

they were on and off, and Mark had another child elsewhere.

(David) He has an affair and gets someone else pregnant.

She took it really badly.

And, obviously, he promised her that he would never

have another child with anyone else.

(David) After everything they've been through,

Kylie is devastated.

But then she becomes pregnant by him again.

(Theresa) When Kylie told me that

she was pregnant with her second child,

I was excited for her.

But I was always scared that this baby

could go the same way as the first baby.

(David) Anxious over the possibility

of losing her second baby, Kylie decides to keep

the child away from Sinclair.

She seeks safety and enters a women's refuge.

(Theresa) She went to a mother and baby house.

And whatever Kylie did with the baby,

they used to write it down

so that Social Services knew

that she was being a good mum.

(David) Over the course of around ten months,

Kylie develops a sense of independence with her child.

However, in July 2012, Sinclair tracks down

the refuge where Kylie is staying.

He assaults her and is sentenced to 22 weeks in prison.

There's now little chance they'll reconcile.

Kylie had said so many times that she would leave him.

But it never happened.

(David) Half-sister Tara is certain

Kylie has left Sinclair for good.

She even hears her make a solemn promise

to their father on his deathbed.

I had a phone call from my other sister, Rebecca,

to say that my dad was down at the hospital,

really poorly with pneumonia.

Dads absolutely hated Mark.

The only reason why he was civil was because he was with Kylie.

Kylie promised our dad that...

that she would never get back with Mark.

And that's when she promised that she'd leave him.

(David) But then the family feels certain

Kylie has found strength through her second son,

away from Sinclair for good.

But then...

Kylie used to secretly meet Mark where she lived.

And Social Services found out.

And because she'd done that, that's why they took the baby.

(David) Kylie's child is taken into care.

Ironically, what that does is make her even more dependent

on Sinclair.

And so that puts even greater control in the hands of Sinclair,

because without Sinclair, Kylie has nothing.

(tense music)

(suspenseful music)

(David) When authorities in Berkshire discover

Kylie has been meeting Sinclair in secret,

they have no option but to offer protection to her second child.

It just breaks my heart.

I felt angry.

I was annoyed because I knew...

That she would always choose Mark.

(Tara) I messaged her, and I said, look,

you made Dad a promise. And she said, I know I did.

But I can't...

I've... that's when she said about the bond,

and he's the only part of her children.

In fact, he probably made himself feel

like the victim of all of this.

You know, he lost his two children with Tara.

He's now lost his two children with Kylie.

Kylie's had her children taken from her.

You know, is she a bad mother?

Is this punishment for her... for her past behaviours, if you like?

(tense music)

So in 2012, Mark and Kylie actually moved out of the area.

Now, one might think, well,

that's an opportunity to start all over again.

But when I read something like that, I'm immediately thinking,

this is quite risky because they're moving

from one police area to a completely different police area,

another local authority area.

So all these partners aren't going to be aware of the history

of Mark and Kylie.

And so had they gone somewhere else to actually almost start

that cycle of violence again,

where they're undetected until such time,

you know, the police are notified?

(David) By 2017, there's clear evidence

that Sinclair's cycle of violence is becoming even more brazen.

There was this particularly nasty incident

where he chased his mother and a police officer

with a meat cleaver.

And it's no surprise that when it came to a review of his risk,

he was deemed high risk.

And for me, that shows that his pattern

and offending behaviour is just getting worse and worse and worse.

But obviously, this then makes it a really high-risk situation

for Kylie, who's in that relationship,

and on a number of occasions has been

the sole victim of his violence.

(David) With Sinclair in a secure unit,

Kylie relocates multiple times, first to an Oxford refuge,

then back to Newbury.

Yet the cycle repeats immediately upon his release, and they reunite.

They go to live with her mother, Theresa,

who quickly notices Sinclair's increasingly strange behaviour.

(suspenseful music)

(Theresa) When Mark used to live at my house,

he used to come into my bedroom at night

and just look at me and watch me sleeping,

which I thought was a bit strange.

(David) Sinclair's mental health issues worsen,

and they are exacerbated by his drug use.

He's now diagnosed with further conditions, including sociopathy.

And then he sells something precious of Kylie's

to a local pub landlord so as to get money to buy drugs.

There will have been umpteen examples of his callousness

in their relationship.

We know, for example, that he sold Kylie's puppy

in order to get money for drugs.

That absolutely sums up the dissocial personality disorder

characteristics that Mark had.

(David) Sinclair strives to convince Kylie

his crimes are her fault.

But Kylie remains trapped,

unable to leave Mark without proper support.

In June 2018, authorities in Berkshire

grow so concerned for her safety that they step in

and initiate a MARAC.

(Paul) A MARAC is a Multi-Agency Risk Assessment Conference,

and it's chaired by an independent person.

And a number of partners are invited to that meeting,

which would include the police.

It may involve probation, housing, local authority, health.

And the idea is that those partners share information

that they have on that particular family.

They identify what those risks are.

It may be that probation can review licence conditions

of an individual.

It might be the police can do some more monitoring around there

or flag the address that, if there are any domestic incidents,

police will respond to urgently.

And so to say, the whole idea is to get this holistic approach

on this family to try and problem-solve

and actually try and stop the violence

happening in the first place.

(David) Authorities contact Kylie's local medical practise

and ask them to encourage her

to engage with domestic abuse services.

Kylie doesn't attend.

But around this time, she decides

she and Mark should live separately.

(Paul) Living separately from him,

she's still in a relationship with him.

And some people might think that's a little bit strange.

What she's probably doing is, she's removing herself

from the risk of day-to-day violence

and that controlling behaviour.

But she's keeping him happy, to a certain extent,

in that she is still in a relationship.

She was saying that she just... she'd had enough

and didn't want to be with him no more.

(David) We know that the most dangerous time for the victim

of domestic abuse is when she, or indeed, he, decides

that they're going to do something about the abuse

they're experiencing by creating space within the relationship,

or indeed leaving.

That's the time at which the threat from the abuser

becomes most acute because the abuser

sees this as a loss of control.

And he will try to reassert his control

to prevent that space in the relationship or to, indeed,

to prevent the victim from leaving the home itself.

And what he might do in that situation is use more violence,

and indeed, on some occasions, use lethal violence.

(tense music)

Theresa is invited to Kylie's new flat

in the village of Theale in West Berkshire to have dinner.

Mark is also there.

I went round there that evening.

We had dinner.

We were laughing and joking around.

It was like a normal day.

(David) Theresa sees no sign that Kylie plans

to end the relationship permanently.

Even if she is, Kylie has good reason to hide it.

Mark said to her, if you leave me, I'll kill you.

I think he... he was almost, in saying this,

I think he was almost trying to warn her

that that is... that is who he is.

(David) Tied to a man who'd rather she died than leave him,

Sinclair hurts Kylie again.

(Paul) We don't know exactly what went on

and what led up to this.

But there was clearly a violent altercation

which resulted in Mark strangling Kylie

to the point of unconsciousness.

(James Aldridge) It was an act of extreme violence.

After Mark rendered Kylie unconscious through strangulation,

he stabbed her in the neck first and then the heart.

So clearly, the violent acts, he knew what he was doing.

Even though maybe a red mist had descended on him,

he knew what he needed to do to...

to render the result that happened.

(Paul) There are two different types of injuries, if you like.

There are the stab wounds, which are violent and very personalised,

and then you've got the strangulation as well.

And this, for me, demonstrates a real anger

and hatred towards that individual.

(David) People get the impression

from watching film or TV drama that strangulation is quite quick.

It can happen literally in seconds.

But if you're going to kill someone through manual strangulation,

it will take three, perhaps even four minutes.

The person can lose consciousness more quickly,

but they won't actually be dead.

And all the time that the perpetrator is strangling,

he is literally looking into the face of his victim,

watching life drain away.

That gives them the ultimate form of power and control.

All of the warnings, all of the interventions,

all of Kylie's fears had proven to be true.

(tense music)

(David) After strangling, stabbing, and ultimately killing Kylie,

Sinclair does something out of character.

Mark had brutally killed Kylie, and then coldly called the police

to say exactly what he'd done.

It's as if the murder is a momentary aberration

to his general personality.

It's indicative of the way that his personality would have seemed

to oscillate between this warm individual

and this person who could be so callous and violent.

(David) Whether Sinclair is calling 999

through genuine guilt or to mitigate his actions,

police quickly arrest him.

They then break the devastating news to her family.

The police came to my house at quarter to 5:00

in the morning and said

that I need to sit down,

that something has happened to my daughter, Kylie.

Of course, I didn't believe it.

I just sat like I was in another world.

I started to cry.

I couldn't believe what I was hearing.

I had a friend call to ask me if I'd heard about my sister.

And obviously, you'd been,

well, what do you mean? type thing.

And they was like, oh, she's been killed.

And I'm like, don't be... don't be stupid.

Do you know what I mean? What... don't mess about.

And then obviously, I rung my other sister,

and she confirmed that... that, actually, yeah,

she'd been murdered.

Obviously, she'd been stabbed in the neck

and straight through her heart.

I just couldn't believe that he'd go that far

or that he'd even do that.

(David) Family liaison officers

arrange for Tara and Theresa to see her for one last time.

The first time after what happened,

I saw my daughter...

In a coffin.

I couldn't believe...

That that was my daughter lying there.

We went in, and she was just laid on in the coffin.

And obviously, she's as... she's as tiny as Theresa is.

But her face was just blown up,

where I'm assuming it's where he strangled her.

It was just... it just wasn't nice to look.

She was absolutely beautiful, don't get me wrong.

But it just wasn't nice to see what he had done.

(solemn music)

(David) Throughout her entire adult life,

Kylie remained loyal to Sinclair.

But could anyone have acted to help her?

He wasn't being managed around his risk.

If he were, then there's certain actions

that police and probation could take.

So it could be regular visiting and monitoring of his behaviour.

It could be for him to undertake

certain courses to address his behaviour.

But when somebody's not being managed in that process,

it's simply just recognising this particular individual

may pose a risk.

And therefore, if a call comes in and his name is linked

to that particular call or the address is linked

to that particular call, then the police

should treat that call as urgent and respond immediately

and do as much as they can to... to address that risk.

I have no doubt that there were people in the... in the services,

within the police that... that saw the warning signs here

only too clearly.

But what can they do?

There has to be some degree of voluntary awareness

on the part of... of the partner.

There has to be some admission of a problem.

There just wasn't that readiness yet in Kylie to see exactly

how much of a risk she was at.

Whether she would have started to comprehend that,

we'll never know.

(David) Following Kylie's death,

the Thames Valley Police state that they aim

to establish if there are any areas or lessons to be learned.

By 2019, authorities intensify their efforts

to build the case against Sinclair as they prepare for trial.

He tells the police he didn't mean to kill Kylie,

claiming that there were mitigating circumstances.

He tried to state that his actions were down

to his personality disorder

and that he shouldn't be convicted of murder,

but he should be convicted of manslaughter.

And this presents, you know, a challenge

for the prosecution team.

(tense music)

(James) It can be haunting seeing someone who's capable

of that violence and them being not very far away

from where you are sitting.

Courts are safe places where there are guards.

But you do get a sense of the seriousness of what's happened.

It can be quite harrowing and haunting

to see a person in the dock... a person in the dock

who's capable of such violence.

(David) The trial exposes Sinclair's explosive nature.

(James) He threw a tantrum.

He stormed out at one point, and he started shouting loudly.

We couldn't see him at that point, but we could hear screams.

(David) Throughout the trial, Sinclair continues to claim

he didn't mean to kill Kylie.

(James) The defence said that it wasn't a premeditated act.

However, it was an act where Mark Sinclair knew the targets

that he needed to kill Kylie in terms of

first strangling her, and then stabbing her through the heart

and in the neck.

They'd look at the previous convictions of Mark as well.

And obviously, doctors would be involved to assess him

around his personality disorder.

But we know lots of people have personality disorders

in this country, but they don't go around strangling

and stabbing people.

(David) Of course, Sinclair is going to try and weaponize

the fact that he's diagnosed as having

an anti-social personality disorder.

He wants to try and create a narrative which sees him

as being less culpable for killing Kylie,

and therefore mitigate the charge down from murder to manslaughter.

But this is really just another form of manipulation.

On the 12th of March 2019, after three hours of deliberation,

the jury returns a verdict.

Mark was convicted of the murder of Kylie,

and he was sentenced to life imprisonment

with a minimum term of 21 years.

As soon as they said that the verdict

had come back murder and not manslaughter,

the relief was just unreal.

Because it just felt like, to me, yes, he got life,

but minimum 21 years, that's still not enough to me.

Nothing will ever be enough.

Do you know what I mean?

But to hear that he...

the verdict of murder, it was just like a massive relief.

And it was just like, we got what we wanted.

(David) At sentencing, Sinclair makes one final request.

(Theresa) Mark said to the judge...

(pensive music)

Please, can I say something?

And the judge said, yes, you can, Mark,

as long as you're not abusive.

Mark said to me, he said, Theresa, can you hear me?

I just totally blanked him.

And he said he was sorry for what he'd done...

And he never planned it.

(David) The judge was clear -

Sinclair was entirely responsible for his actions.

(James) The judge in the case

said Kylie wasn't able to remove herself

from a very dangerous person and a very dangerous situation,

and said for the family to not beat themselves up

over what had happened because he... he sort of said that it was,

in a way, unavoidable.

And they shouldn't take shame in what happened because

there... there was something binding them.

But sadly, that did prove fatal.

(David) Sinclair was the one responsible for this ultimate act

of violence and for all the years of pain that Kylie suffered.

But today, her family focus is on honouring her memory

with love and affection.

(Theresa) I miss the fun we had...

The laughs we had...

Even the arguments we had.

But we still had a love, mother and daughter.

(solemn music)

Subtitles by accessibility@itv.com