[Paul Ellzey] I've got a monster out there who did something hideous
and needs off the street quickly.
It was just a purely rage-filled revenge attack.
She was naive about life, as innocent as it could be.
[Andy Beach] She got a scholarship at the Art Institute of Dallas
and she was on her way.
She was thinking she just didn't have time for the relationship.
She just wanted to cut him loose.
He's obviously going to feel rejected and left out.
So it's just a recipe for violence and murder.
[Beach] She confided she was sexually attracted to her.
[Roots Gadhia] She had access to the apartment.
Suggests that she may have been the killer.
[Beach] He hated that girl. She was standing in the way
between a boy that he was interested in romantically.
[Ellzey] I said, "You're the only person right now that would have motive to do this."
I tell him he's a murderer
after we caught him in lies.
[narrator] Every day in North America dozens of people are murdered.
The key to solving the toughest of these homicides
lies in the final 24 hours of the victim's life.
To crack the case,
detectives must reconstruct that critical timeline.
The minutes and hours containing evidence
that can help unlock the mystery
and catch the killer.
[narrator] Dallas, Texas,
the third-largest city in the Lone Star State.
It long ago outgrew its roots in oil and cattle ranching
to become a hub of commerce, high-tech and the arts.
Dallas is a very diverse city.
There's still the Old Line Baptist churches in Dallas
and there's a thriving LGBTQ community in Dallas.
The atmosphere is...
I would like to call it eclectic.
[Beach] There are three different universities in Dallas.
Lots of college students.
It's an exciting place to be when you're young.
[Ellzey] But with burglaries, robberies, rapes,
property crimes and, unfortunately, homicides.
[narrator] Just after 12:00 p.m.
on a Friday afternoon in early September,
a 911 call comes in
from a resident of a student housing complex known as the Falls.
I was in the office and dispatch called us
and notified us that they had a homicide.
The only thing we knew is that it was a female in an apartment complex.
[narrator] Veteran detective Paul Ellzey of the Dallas Police Department
is called to the scene to investigate.
[Beach] Ashley Olvera was the individual that called 911.
She was there to meet the police
when they came at the scene of the murder.
There were no signs of forced entry.
The door was not damaged.
[Ellzey] I didn't see any broken windows, no blood, no bullet holes.
Everything looked fine until you entered the bedroom.
It was just a horrific sight.
There was blood everywhere.
It had been there for a while.
And you could tell because there was a lot of dried blood.
The smell of death reeked in the room.
I saw a young lady with a t-shirt on.
She's got her underwear on. That's all.
Laying face-down in bed.
As I looked closer she's got stab wounds on her back,
stab wounds on her neck, stab wounds on the right side
and it was a very, very brutal crime scene.
The covers were messed up.
But there was no lamps turned over,
there was nothing broken.
I mean it looks like she was maybe sleeping on her stomach
and caught unsuspecting.
[Beach] It appeared like her assailant had just pounced on her
when she was completely helpless and unable to defend herself.
[Ellzey] I've been around the block.
I've seen some pretty horrible things.
You see things done to human bodies that should never happen.
[Beach] It was a gruesome, gruesome scene
and deeply affected these hardened investigators
to see just how this girl had been destroyed.
[narrator] The victim is 20-year-old Samantha Nance known as Shelley,
a sophomore at the prestigious Art Institute of Dallas.
[Ellzey] She had come from a town called Italy, Texas.
Italy is a little bitty small bedroom community.
Shelley was the third and youngest daughter in a family of five.
And her family was very close.
[Beach] Shelley was an introvert.
From an early age, painting was her outlet.
She entered a contest in her junior year in high school,
she won that contest,
and got a scholarship at the Art Institute of Dallas and she was on her way.
[Hannah Cooper] Shelley wasn't the typical college student.
She wasn't going out partying.
She pretty much liked to stay at home
playing a video game,
listening to music and drawing.
You couldn't dislike Shelley Nance. She was a beautiful soul.
[narrator] To track down Shelley Nance's killer,
investigators will need to piece together
the last 24 hours of her life.
Obviously one of the important things
we're looking for is the approximate time of death.
So based on her body's state and condition,
the medical examiner estimated the time of death
was approximately 24 hours prior to her being found.
And his best guesstimate
was between 9:00 a.m. and 12-noon the prior day,
Thursday, which would be the morning of the 10th.
[narrator] With a broad window of death established,
police begin processing the crime scene.
[Ellzey] We noticed that there was a little bitty sliver of a blue plastic material,
that was, I believe, on her arm close to her hand,
that just didn't fit.
I didn't see anything in the apartment that it would have come from.
So that was bagged and tagged and sent to the crime lab for analysis.
[narrator] Investigators get another surprise when they enter the bathroom.
[Ellzey] One sink has two three little
small drops of blood, that you can tell.
[Gindratt] My thinking is maybe the killer cleaned up before they left
and if they were injured, it could've been their own blood.
[Beach] They collected swabs for future comparison whether it be to Shelley
or, potentially, to the individual that murdered Shelley Nance.
[narrator] The rest of the apartment seems untouched
except for one thing.
[Ellzey] We got to the kitchen and they had a set of knives in there.
And Ashley looked at it and she thought that
at least one or maybe two knives weren't there.
They weren't in the dishwasher,
they weren't in the sink, they couldn't be accounted for.
So at that point,
maybe the killer did not bring a weapon with him
and used a weapon at the scene.
It could be a possibility. We don't know.
[narrator] Investigators work to develop a theory of the crime.
I'm trying to think of a motive.
Everything looked in place in the apartment.
Her laptop was there.
Things that is normally taken during a burglary is still there.
Shelley had her underwear on.
So immediately I thought, well, maybe sexual assault is not a motive.
[narrator] Looking for answers to what went on
during the final 24 hours of Shelley's life,
detectives turn to the forensics.
They were able to determine that Shelley
had been on her laptop from about midnight
to almost 6:00 in the morning of September the 10th.
Just doing schoolwork.
At about 5:57 a.m.,
Shelley signed off and she finally went to sleep.
[Ellzey] So what happened really, really bad, happened after 6:00 a.m.
Any time a person is attacked and murdered with a knife,
it's been my experience that it's something very personal,
that they generally know the victim.
Because when you use a knife on somebody,
you have to get in their space.
I mean, you want them to know what's happening.
[Beach] Shelley wasn't killed, she was overkilled.
This was a crime of hate.
A crime of passion.
[Ellzey] The closest person to her inside this apartment is Ashley.
We have to establish that she's telling the truth, where her whereabouts are
and see if she has a motive for such a heinous crime.
[narrator] Investigators bring Shelley's roommate, Ashley Olvera,
down to the police station for an interview.
[Ellzey] Ashley's demeanor was not the kind of demeanor I would expect
had my roommate got murdered.
She was kinda monotone.
Or maybe she was in shock. I don't know.
Ashley was also a student at the Dallas Art Institute.
She was Shelley's roommate.
Had been for two, three months.
But they didn't have what I would consider a normal female relationship.
You know, if you got two girls living under one roof,
and I can tell you this because I've had two daughters,
they're fussing over the bathroom, they're fussing over food.
That wasn't happening.
Shelley stayed in her room.
She took care of her business, very quiet, to the point that
Ashley sometimes didn't even know if she was home.
And she was asked, obviously, what she was doing the morning of the 10th.
She was in class all day long.
And then she left about 3:30 or 4:00 that afternoon to go back home.
[Ellzey] When we asked if she noticed if Shelley was home
when she got home that afternoon.
She stated she didn't know.
She assumed she was.
But she was quiet.
[Beach] So Ashley didn't see Shelley.
She didn't think anything of it because they would go,
you know, hours, sometimes a day at a time,
they wouldn't see each other at the apartment.
[narrator] The next day, Ashley had left for school at the same time, 8:00 a.m.
But around 9:45 a.m.,
an administrator had approached her.
The school had received a call from Shelley's parents
who hadn't heard from her in over 24 hours.
They asked Ashley if she knew where Shelley was.
Ashley assumed Shelley was still in her room back at the apartment.
[Ellzey] They asked her to go home and check on Shelley.
She gets to her apartment at about 11:45 a.m.
She knocks on the door, yells for Shelley, she don't get an answer.
She knocked again. No answer.
After the second time she knocked with no answer,
she opened the door.
And inside the room it's dimly lit
because the curtains are pulled.
So she walks up, grabs Shelley by a foot, kinda shakes her,
and she's cold.
It startles her.
And she saw what the monster had did.
[Beach] Ashley Olvera then called 911.
[narrator] Detectives find it strange
that Ashley hadn't noticed that Shelley had been lying dead in her room for 24 hours.
[Gadhia] The simple oddity of her not having any contact with her roommate
suggests that potentially she may have been the killer.
She had access to the apartment.
She had access to her roommate.
[Ellzey] I said, "I just gotta tell you you're the only person I'm looking at,
you're the only person right now that would have motive to do this."
I said, "What the hell happened between you
and Shelley that went so horribly bad that it resulted in this?
Why did you do this?"
[narrator] In the brutal stabbing
of 20-year-old art student, Shelley Nance,
investigators have her roommate and classmate,
Ashley Olvera, in their sights.
[Ellzey] When I asked her if she was in the bathroom that morning
to get ready to go to school, she said she was.
I asked her if she noticed the blood.
[Ellzey] And I asked her, I said, "You know, why in the world
would you see blood in there and you didn't care enough about her to knock on the door
and say, 'Hey, are you okay? Are you bleeding? What's up?'"
She said she didn't register. It didn't mean anything to her.
And I thought that kinda odd.
I asked her, I says, "You've been roommates for a while
and there's conflicts that comes with that."
Then I accused her of killing her.
And she said, "I didn't do it."
Not very emotional,
not, "Oh, my God, you're accusing of murder. This is my roommate."
"I didn't do it. I didn't do it. I would not do it."
[narrator] Despite their suspicions,
investigators need more evidence to arrest Ashley
and are forced to let her go.
It certainly seems that
Ashley would have had the opportunity
to murder Shelley.
But what investigators don't know is,
"Why would she?"
That a question they want answered
before they make their next move.
[narrator] Detectives reach out to Shelley's mom, Cynthia Nance,
hoping she can shed more light on Shelley
and who might have wanted to hurt her.
[Beach] Obviously, the police were interested in finding out
from Cynthia, who was close to Shelley, did she have a boyfriend?
Did she have any known enemies?
In Cynthia's eyes, Shelley had never met anybody
that just didn't immediately warm up to her.
Cynthia was racking her brain about who could've done this.
And really the only individual that kinda kept rolling around in Cynthia's mind
was this boy that her daughter had dated a few times.
We learn that she has a boyfriend named Nathan.
And that they haven't been going together very long. About a couple of months.
[Beach] Their big deal was going to anime festivals and they were both into that.
But Cynthia thought it was significant that
about two weeks before Shelley's murder,
Shelley had told Cynthia that she was going to break up with Nathan.
She was thinking about telling him that,
you know, she just didn't have time for the relationship.
It wasn't going in the direction that she thought it should go
and she just wanted to cut him loose.
So Nathan now becomes a person of interest
that we need to locate
and get down there and start interviewing him.
[narrator] Detectives bring 20-year-old art student Nathan Shuck
down to the station for an interview.
[Ellzey] I said, "Nathan, you're down here
because a crime happened to Shelley. She was found murdered."
And it's like it just went in one ear and out the other.
Like it don't register.
Not very emotional.
He's like, "What?"
I don't know if the guy's in shock.
He just didn't have the reaction that I would think.
[narrator] At first, Nathan seems like an unlikely killer.
The best way to describe Nathan was he was 19 going on about 13.
[Ellzey] He was just a little bitty skinny guy who likes art.
His mom raised him and he's doted on.
[Beach] Nathan still, even though he was living there in town, in Dallas,
he would go home days at a time.
His momma would cut the crusts off his bread
like she had done since he was about three years old.
I says, "What the hell happened?"
And I probably even fibbed to him a little bit and said,
"Well, you know, you're the last person seen with her alive.
You was over at her apartment."
He's like, "No, no, no, no, no. I didn't do it.
You need to look for somebody else."
[narrator] Looking for a motive,
detectives push him for details about his and Shelley's relationship.
[Beach] They were both new at the dating game.
So they were taking things slow.
[Ellzey] I asked him, "What is the extent of your relationship?
Are you sexually involved with Shelley?"
Just a very unusual boyfriend-girlfriend relationship.
[narrator] Detectives believe that if Nathan is the killer,
he may have defensive injuries from the struggle with Shelley.
[Beach] Nathan explained to him he was a fidgety sleeper,
he didn't trim his fingernails like he probably should have.
And these were self-inflicted in the middle of the night.
But they could've been from Shelley fighting back.
[narrator] Detectives drill down on Nathan's whereabouts
during the window of time when Shelley was killed.
[Ellzey] We're trying to get his timeline established.
And I asked him the last time he either talked to her in person
or by telephone, when he talked to Shelley.
[Ellzey] I also asked Nathan
the last time he physically saw Shelley.
And he told me that him and her
had attended an art festival downtown.
[Ellzey] I asked him what happened after the art show
that they had attended. Where did he go?
Did he go to her house or his apartment?
He said, no, that he went to his mom's house.
[Beach] Nathan had been sick and he was sick enough
that he decided to go home to his mom
and get some home cooking and sleep in his own bed.
Nathan told his mom the day before the murder
that he was feeling better
and he wanted to go to school the next day.
His mom drove Nathan in from their home
on the morning of September the 10th
and dropped him off at his apartment.
[narrator] Prompted by Cynthia's knowledge of their impending break-up,
detectives dig deeper into the state of Nathan and Shelley's relationship.
[Ellzey] He had no idea that Shelley was gonna
share that kind of information with him.
So if he was jealous, which is sometimes motive for violence,
that wasn't on the radar.
[Beach] But there is about a three-hour,
four-hour time gap
between 9:00 and about 1:00
of the afternoon of September the 10th
where Nathan is basically unaccounted for.
[Ellzey] So he would still have had the opportunity to commit this crime
and we still needed to look at him as a suspect.
[narrator] With suspicion swirling around Nathan,
police ask to search his apartment
looking for evidence to connect him to the crime.
[Ellzey] This was a horrendous crime with a lot of blood evidence.
So it's reasonable to believe that
whoever attacked her also had blood transfer on him.
So we're walking through the apartment
looking for bloody clothes, looking for a pair of shoes
that may have a speck or a drop of blood on them.
And we're looking for weapons,
but, at this point, we just know that it's a sharp instrument.
We still don't know if it's a knife,
or if it's a pair of scissors,
a piece of gla-- We don't know.
We're going through drawers,
we're going through dirty clothes hampers.
We don't see any blood evidence,
we don't see any clothing
that's got any evidence that we're interested in.
And when we get to Nathan's room,
we open up a box.
It's got knives, it has daggers,
it has Japanese throwing stars,
it's got swords.
[Beach] These were high-quality knives.
An unusual collection
for a 19-year-old kid to have under his bed.
And the detectives confronted Nathan.
He goes, "That's what I'm into,
I've been into the ninja mentality, the anime,
that whole genre since I was a little kid."
Weird stuff, weird stuff.
And then we walk into a bathroom
and beside the sink there's a plastic ziplock baggie.
[Beach] You could see what appeared to be matted hair
and what appeared to be blood
on the inside of the ziplock baggie.
That's the moment that I really got excited.
I was hoping and praying,
"Please, let the lab confirm
that these are Shelley's blood and Shelley's hairs."
And I asked Nathan I says, "Whose bathroom is this?"
He says, "It's mine."
I said, "What's that plastic bag there?"
And he looked at it and immediately
had a "Oh, [bleep]!" look on his face.
And he says, "I think I need a lawyer."
That little boy that I was talking to,
now made a statement like a grown man.
Like somebody who has something to hide would say.
We're through. Stick a fork in it, I'm done.
There can be no other guy who committed this murder except Nathan.
[narrator] In the horrific stabbing
of 20-year-old art student Shelley Nance,
investigators are zeroing in on her boyfriend, Nathan Shuck.
You got a kid that was dating the victim,
whose mom was saying the victim was getting ready to broke up with.
So you got motive,
you've got opportunity
because he's still seeing Shelley,
has access to Shelley.
And now you've got potential murder weapons underneath the bed.
And then the cherry on top was this ziplock bag
with blood and hair.
[Ellzey] But I have no idea whose blood that is until we get DNA back on it
and it takes time.
We don't have enough to arrest him for it.
His timeline that he gave us still needs to be validated and checked out.
So I released Nathan that day.
[narrator] To build their case against Nathan,
investigators turn to the autopsy results
which revealed disturbing insights into the killer's mindset.
There were not any observable signs
that she had been sexually assaulted.
But there were 42 individual stab wounds.
Some of them less than an inch in depth.
Some of them over 3 inches.
So it's clear to law enforcement
that the killer enjoyed what he was doing.
[Arntfield] When you see this type of array of stab wounds on a victim's body,
not only the sheer number,
fluctuating depths and locations suggest one of two things.
You're dealing with a sexual sadist
who's obtaining pleasure
and prolonging this for their own gratification
or, alternatively, you're dealing with someone
who has such deep-seated, visceral hatred of the victim
that they want to ensure the maximum level of agony.
[Ellzey] To continue their investigation into Nathan's possible role
in the murder of Shelley Nance,
they're gonna talk to everybody they could talk to,
to find out, "What do you know about Nathan?"
[Ellzey] During the initial interview that I had with Nathan,
he told me that he shared an apartment with another male.
He identified him as a guy named Daniel.
[Beach] Daniel Willyam was not your typical Art Institute student.
He was five to six years older.
He'd been in the Navy. He's seen more of the world.
I look at Daniel,
I see a little bitty short, pudgy,
non-threatening, soft-spoken...
[Ellzey] When I talk to Daniel about the relationship he has with Nathan,
it just gets weirder.
[Beach] Daniel told the police he was openly gay,
but assured the police that his relationship with Nathan was strictly platonic.
[Ellzey] But Daniel let it be known that he doted over Nathan.
Cooked him breakfast, made sure that he had a lunch to take to school.
When he was available he would shuttle him to and forth from class.
I mean, he did everything but wash him and wipe his butt.
Come to find out that Daniel knew Shelley, he didn't like Shelley,
he expressed that he didn't think Shelley was good for Nathan,
that she was a distractor.
[Beach] Nathan, it appeared to Daniel, had become obsessed with Shelley,
that he began stalking Shelley,
that Nathan's schoolwork was suffering because of his deep feelings for Shelley.
[Ellzey] And it's like a parent talking to a kid in a troubled relationship.
"Stay away from this person, they're not good for you.
You know, you need to cut them loose.
And you need to focus on school."
Just a very weird, unusual situation.
[narrator] Intrigued with the nature of their close friendship,
detectives question Daniel for his account of events the day of the murder.
[Ellzey] "What time did Nathan get here?"
"He got here yesterday morning when his mom dropped him off.
I took him to school and dropped him off."
I said, "What time was that?"
He said, "8:30."
I said, "Okay. What did you do next?"
He said, "Well, I had an assignment that I had to take care of."
He said that he had to go photograph something
at one of our local parks called White Rock Lake.
But he forgot his camera, which is kind of strange.
I asked him what he did when he got to the lake
and he said, "Well, I went to my friend Jessica's house."
I said, "Was she home?" He says, "No."
"What did you do then?"
"I just turned around and went home."
"What time would you have got back home?"
He said, "Around 9:00, something like that."
He wasn't sure.
[narrator] Daniel then reveals that he is also good friends
with Ashley Olvera, Shelley's roommate.
This immediately piques the investigator's interest.
Daniel told police that Ashley confided in Daniel that
she was sexually attracted to Shelley.
This is the first time that the Dallas Police had heard anything about that.
[Ellzey] He summed it up as maybe she was having some thoughts of being gay
or was contemplating experimenting with a gay relationship.
[narrator] Armed with this new information,
detectives begin to consider a new theory of the crime.
Could Ashley have had a crush on Shelley
that wasn't reciprocated, leading to murder?
[Ellzey] This case has got twists and turns, crazy motives,
unusual relationships,
and it just gets weirder.
We asked Ashley about what we had learned from Daniel
as to her struggling with her sexuality.
She validated that that was a true statement.
I asked her if she was, at any time, had any romantic feelings for Shelley.
She said, "Absolutely not."
Her and Shelley didn't have anything in common
other than they shared the same roof
and they went to the same class.
[Beach] When they specifically asked her about
Daniel's portrayal of the relationship
between Nathan and Shelley and how Nathan had become obsessed,
Ashley painted a completely different picture
of the relationship between Nathan and Shelley
that Daniel was trying to portray.
[Gindratt] The roommate tells us that
if anyone is obsessed with anyone else,
it's Daniel who seems to be obsessed with Nathan.
[narrator] With Daniel and Ashley offering
two different versions of events,
detectives' suspicion are aroused.
[Keira Stockdale] Typically, it's human behavior to lie.
The question is, "Why?"
And are we lying because we're ashamed
and we're trying to conceal information
that's not related to the crime?
Or are we lying because we have
guilty knowledge or involvement
and we're trying to cover up our actions?
[narrator] In the brutal murder
of 20-year-old art student, Shelley Nance,
detectives have two suspects in their crosshairs.
Her boyfriend, Nathan Shuck,
and her roommate, Ashley Olvera.
But new information has introduced a possible third suspect.
Daniel didn't want Nathan to be alone with Shelley.
Daniel expressed dissatisfaction to Ashley
about Shelley being around Nathan.
[Cooper] He constantly talks about it.
It always ends up the conversation being about Shelley
and how much he despises her.
It's non-stop negativity towards Shelley.
[Ellzey] Shelley has shared with Ashley that Daniel had texted Shelley
asking could he go along
and be involved when they went out.
Like the weekend that they went to the convention.
Not only on that occasion, but prior occasions,
and she felt that a little weird.
You know, you don't invite a third wheel out on a date.
Shelley got vibrations that something wasn't right.
She sensed that if Daniel had his way,
he would have liked to see her out of the picture
so he could pursue Nathan
and maybe escalate that to another level.
[narrator] Ashley then reveals that
on the day Shelley was murdered,
Daniel bombarded her with texts.
[Ellzey] We found out that he had texted Ashley
at 10:02 a.m. and they had a conversation.
And basically it was questions about,
"Where you at? What are you doing?
Do you want to go for lunch? Do you wanna meet me?"
She said, "No. I don't think so. I'm in class."
And then he texts Ashley again about two hours later, exactly at 12:03 p.m.,
and he's asking her again,
"Are you still at school? Are you going home?
Are you sure you don't wanna go for lunch?"
She's like, "No. I'm fine. I'm staying at school. I'll eat lunch here."
[Beach] This was unusual for Daniel to be sending a flurry of texts to Ashley.
Shelley Nance was murdered sometime between 9:00 a.m. and noon.
And with that timeframe in mind,
the text messages, now, between Daniel Willyam and Ashley Olvera
took on added significance.
[Ellzey] What we implied from that is that he was
trying to make sure that she wasn't at home
and that where she was at between those hours.
[Beach] Before the interview wrapped up,
the detective asked Ashley if there was anything else
she thought they would be interested in,
that might help in the investigation.
Ashley remembered about 10 days before the murder
that Daniel had locked his keys in his own car,
he was in a hurry and he asked to borrow Ashley's car.
[Ellzey] I asked her to check to see if it was still there
and she said it was still there,
but she thought it had been taken off
and put back on and I asked her why.
And then that's when she mentioned,
"It used to be in the middle but now it's on the end
and it used to be flipped this way,
but it's flipped the other way.
And I've realized now that
when I put my key in something was different,
but I didn't realize it until you just mentioned it."
There was no signs of forced entry.
So Daniel had the opportunity
to have a key made if he had wanted to.
Based on the time that this occurred,
he has a motive,
he has the opportunity,
he has the means to gain entry without being detected.
Daniel's looking pretty good right now.
[Stockdale] It's entirely possible for somebody to be in a love triangle
where somebody is, you know, trying to obtain the affection
from one person and upset
because they feel potentially rejected and left out.
It's just a recipe for violence and murder.
[Ellzey] So now we have three suspects.
We have Ashley,
we have Nathan
and we have Daniel.
Now we have to go through the process of elimination.
The detectives were able to validate through witness interviews,
time stamps and surveillance video
at the school, that Ashley was in school
between 9:00 a.m. and 12-noon.
So, she's got a pretty good alibi.
[narrator] With Ashley eliminated as a suspect,
investigators shift their focus to Daniel Willyam.
They want to go over again Daniel's timeline about the events
of the morning of September the 10th.
And I think Daniel was confident.
He had no problem talking to police a second time.
[Ellzey] And he tells us, "Yes, I went to White Rock Lake,
directly there to do a photoshoot
after I dropped Nathan off at school."
I asked him what time he got to White Rock Lake.
He said," Around 8:30. Maybe a little bit after."
"Okay. What did you do then?"
"Uh, well, I went to Walmart."
Walmart?
[Beach] Just that little, seemingly innocuous point
about Daniel going to the Walmart,
they said, "Wait a minute. He didn't say anything
about going to the Walmart the first time we talked to him."
[Ellzey] "How long was you at Walmart?" "Not very long."
"What did you buy at Walmart?"
He said, "Well, I bought some hair color,
I bought something else, two or three items."
"What happened after you left Walmart?"
"Well, I went to see a girl
that lives in the Falls apartments."
"What for?"
"Well, I just went to visit her."
So I asked him, "What time did you get there?"
"I don't know. 11:00, 11:30."
I said, "Was she home?" "No."
Now this is the same complex that Shelley lives in.
[Beach] And this is like a double "whoops" now for the police.
Of all the apartment complexes in Dallas County,
he's at the apartment complex
at about the time when Shelley Nance is murdered
on September the 10th of 2009.
So the fact that he didn't add that before
was definitely a bomb that we were taken aback by.
[Beach] So, let's just say that the interest
in Daniel Willyam now is becoming real important.
[Ellzey] Time is wasting.
I've got a monster out there who did something hideous
that needs off the street quickly.
[narrator] In the brutal murder of Shelley Nance,
police have a surprising new suspect in their sights...
The roommate of Shelley's boyfriend, Nathan,
a fellow art student named Daniel Willyam.
By his own admission,
he put hisself at the crime scene
during the time this murder occurred.
[narrator] With questionable new information coming to light,
detectives dig into Daniel's story
to see if his timeline checks out.
Walmarts, they have surveillance video.
[Ellzey] You can see Daniel.
He's got his phone. He's texting.
This is at 10:02.
It corresponds with the text he's sending Ashley
asking her where she's at, what she's doing, does she wanna go to lunch.
[Beach] And there he is. Just like he said he was.
Daniel told him he purchased a bar of soap,
he told the police he purchased a hair dye,
what he didn't tell the police was that he purchased another item
and that was a package of blue nitrile gloves.
We remembered that little bitty blue piece
of nitrile glove material found on her body.
[Beach] The police were able to go back out and buy
a duplicate box of the blue nitrile gloves
with the hopes of being able to conduct a forensic comparison
between the piece of blue plastic found on Shelley Nance's arm
and the blue nitrile gloves that Daniel Willyam had bought.
[narrator] Then the results come in
from the forensic evidence collected at the crime scene
and from Nathan and Daniel's apartment.
[Beach] Probably the most significant finding
of all the items seized
at the scene of Shelley Nance's murder is, number one,
the blood evidence found there in the sink
in the bathroom in her apartment,
and the DNA came back that that was the blood of Shelley Nance.
Of equal importance the police got back
information concerning
whose DNA it was in the ziplock baggie
with the blood and hair in it
the police found
in the bathroom of Nathan Shuck.
And that also came back to be the DNA of Shelley Nance.
Now you have the DNA,
the blood and hair of the murder victim
in the apartment of Nathan Shuck
and in the apartment of Daniel Willyam.
[narrator] Detectives now know that either Nathan or Daniel killed Shelley Nance.
But which one had the opportunity?
Nathan is validated being at school by surveillance video
and other students put him in class
between 9:00 a.m. and 2:00 p.m. the day
the murder occurred.
So after we're able to establish an alibi
that Nathan could not have did it,
the only person left is Daniel.
So we have a third interview with Daniel.
He's tense.
He's nervous.
And I dig into him hard.
I tell him he's a murderer.
I tell him he did it.
After we caught him in lies,
we've already pulled his surveillance video
the day before Shelley was found dead
that he was at Walmart buying plastic gloves.
I pulled a picture of Shelley out
and I show him a picture of the crime scene.
It was gruesome to look at and he just covered his face and cried like a baby.
Said he didn't do it. Didn't do it. No, he didn't do it.
[narrator] Then a final piece of forensic evidence seals Daniel's fate.
The most important piece of evidence
was that little bitty blue speck of plastic.
The lab was able to take that little piece of plastic
and scientifically compare it to the box of gloves
that Daniel was observed buying at Walmart on videotape.
And scientifically confirm that that piece of plastic was of the same material,
same roll, same consistency
of material that those gloves that he purchased was from.
So that put him at the crime scene.
I'm telling you, he had means to do it,
he had motive to do it,
he had opportunity to do it.
And by his own admission,
he put hisself at the crime scene
during the time this murder occurred.
[Beach] He hated that girl.
She was standing in the way between Daniel and Nathan Shuck,
a boy that he was interested in romantically.
[narrator] Detectives are now able to piece together
Shelley Nance's final 24 hours.
[Beach] We know that Shelley and her mom spoke with each other
on the night of Wednesday, September the 9th.
[Ellzey] After the conversation with her mom,
Shelley stayed up all night long
and on her computer from midnight till 6:00 a.m. the next morning.
[Gindratt] She falls asleep while using the laptop
until Ashley goes to school that morning at 8:00.
[Ellzey] Daniel dropped Nathan off at school about 8:30.
Then he said he went to White Rock Lake,
went to Walmart.
[Beach] Daniel Willyam purchased
a bar of soap, hair dye,
and a box of blue nitrile plastic gloves.
Daniel was texting Ashley repeatedly
between 10:02 a.m. that morning
and about 12:00 that morning
asking about going to lunch with her, where she is.
It's apparent that Daniel is very concerned about Ashley Olvera's whereabouts
during this timeframe.
Daniel ended up at the Falls apartments around 11:00.
[Beach] He had made a copy
of Ashley Olvera's front door key.
He let himself into that apartment,
and went back to that bedroom
where that little girl was sleeping.
[Ellzey] He was able to enter the apartment undetected,
pounce on her back,
stab her 42 times.
He'd worn those blue plastic gloves to make sure
he didn't leave any fingerprints.
He didn't see that little piece of blue plastic
that had come off during the savage assault.
[Cooper] So while Daniel's alibi maybe wasn't locked down super tight.
I think it shows that he had a lot of pre-planning,
forethought, premeditation,
whatever word you wanna put on it.
[Arntfield] Nathan's affection is shown towards Shelley and not Daniel,
who is, for all intents and purposes, acting like a romantic partner
and doing favors for him and running errands for him.
That Nathan isn't going to recognize
his affectionate gestures for what they are
and ultimately Daniel decides that
he needs to remove Shelley from the equation.
[Cooper] It was just a purely rage-filled revenge attack
because he loathed Shelley.
[narrator] On December 8th, 2009,
Daniel Willyam is charged with the first-degree murder of Samantha "Shelley" Nance.
[Ellzey] I've seen things did to a human body that you can't imagine,
but the scene of that little girl laying in that bed,
with those stab wounds,
I'll never forget it.
[narrator] He's found guilty
and sentenced to life in prison.
[Beach] The timeline was there
from Daniel Willyam's own cell phone,
to the surveillance video at Walmart
to the medical examiner's opinion on time of death.
Everything fit like a blue nitrile glove.
[Ellzey] I went to Shelley's funeral.
She's the only victim
that I've worked in my entire career
that I went to her funeral. I did.
I just felt I needed to be there.
[Beach] The good thing for me,
when I had recurring nightmares about my daughter,
is I could wake up
and realize it was just a nightmare.
That she was still around.
Sam and Cynthia,
and Shelley's sisters,
they don't have that luxury.
So, yeah, this was personal.
It was personal back in 2009.
It'll be personal till the day I die.