[TEXTING]
BRANDON MUIR: We discovered that one of the phone numbers
that she'd been in contact with the day she disappeared
was Colter Peterson.
MOTHER: That was a clue because they had already
talked to Colter Peterson.
And he's like, yeah, I haven't talked
to her in, like, I don't know when, six months or something.
[TEXTING]
BRANDON MUIR: At one point, we received an eyewitness
account that said they had seen two
males walking down the road.
And one of them was wearing a multicolored backpack.
[TEXTING]
We were able to retrieve a doorbell camera that showed
the two individuals walking past the home,
carrying the multicolored backpack, just prior to 5:00
PM on that day.
We knew that they were taking care of the investigation.
We were more concerned about Des and how she was doing.
FATHER: As she's laying there in the hospital,
her lung had collapsed.
They were afraid they were going to have to do a tracheotomy.
I was like, oh, please, let's just
hold off just a little bit, see if she'll come around.
[TEXTING]
Now, at this point, we had no confession.
We had no solid evidence that it was him.
We needed this interview.
He said that after school, he had left with Jayzon,
gone to his house, played a couple of video games,
and then walked to Jayzon's house,
where they played video games for a couple of hours.
At some point, he said they went to a local convenience store
and bought some drinks and snacks
and then returned to Jayzon's house to play some video games.
[TEXTING]
The timeline didn't add up.
There was a gap in the time that was unaccounted for.
And it happened to be the same time frame that Deserae's
phone had been turned off.
[TEXTING]
Jayzon denied any involvement.
He was claiming that Colter had left
the house for a brief period of time and come back
and didn't know where he'd been.
We continued to interview Colter.
We actually told Colter that Deserae was dead.
We saw his body language slump.
We saw all the reactions that you see in a typical interview
when somebody knows something, and they're not disclosing it.
[TEXTING]
He eventually admitted he had used the gun
to the back of her head and been the one
that pulled the trigger.
Colter was claiming sole responsibility.
And so on that night, we actually released Jayzon Decker
and we arrested Colter for attempted murder.
[TEXTING]
He claimed sole responsibility, which didn't make sense
in our heads because he was with Jayzon Decker
this entire time on camera.
SUE HINTZE: When we found out that it was a boy that she
actually really liked and wanted to spend time with,
it was so sad and shocking.
[TEXTING]
BRANDON MUIR: We were able to obtain detailed phone
records of our suspects.
They had gone out of their way to make sure
that their phones had been in airplane mode
and that their GPS trackers were turned off.
They forgot to turn off their Wi-Fi.
We were able to take Wi-Fi information
and triangulate their location on the canal
at the time of the crime, which later helped us to place
them both on the crime scene.
[TEXTING]
He gave us three different versions of the story
through the course of that interview.
In the third version, he admitted to being at the canal
when Colter pulled the trigger.
His story is that he feared for his life
and felt that Colter was going to kill
him if he said anything.
He told us that Colter had taken her cell phone and her tablet
and destroyed them and thrown them in the canal.
[TEXTING]
I don't think that Deserae had ever deleted
anything from her phone.
When we downloaded her phone records,
I recall there being more than 40,000 pages of information,
lots and lots of text messages.
And the day of the incident, Deserae
had been wanting to buy a pocket knife
and had communicated that to Colter,
and that Colter had a pocket knife
that he wanted to sell to her.
Well, we later discovered that was a guise to get
Deserae to come to the canal.
[TEXTING]
We found a conversation, what seemed to be a plan, something
that had been predetermined.
They were plotting something.
Jayzon asked him if he would hurry up,
and Colter asked if everything was clear.
And Jayzon responded, yeah, it's clear.
I believe it was Jayzon texted Colter the signal to shoot her.
BRANDON MUIR: We started to discover that Colter
was really impressionable.
But Jayzon was also a little bit of a manipulator.