Agent John Walker (U.S. Marshals Service)

FX presents Welcome to Wrexham. For the last four years, it's been this rollercoaster of magic. The Emmy Award-winning series returns.

FX presents Welcome to Wrexham. For the last four years, it's been this rollercoaster of magic. The Emmy Award-winning series returns.

All new Thursdays at 9 on FX. Stream on Hulu.

All new Thursdays at 9 on FX. Stream on Hulu.

There was all kinds of leads coming in. We were looking at everybody. Everybody was looked at.

There was all kinds of leads coming in. We were looking at everybody. Everybody was looked at.

There was a point in the investigation to where the FBI agent and Dykus, the TBI agent, come up with a suspect. And who was that guy? That's Terry Britt.

There was a point in the investigation to where the FBI agent and Dykus, the TBI agent, come up with a suspect. And who was that guy? That's Terry Britt.

We can map her phone to the minute. And that's exactly what I did.

We can map her phone to the minute. And that's exactly what I did.

Let's look at this map. Now this, this information, that is a cell dump of Holly's phone that morning. That means anything that Holly's phone registered on during that time is on this.

Let's look at this map. Now this, this information, that is a cell dump of Holly's phone that morning. That means anything that Holly's phone registered on during that time is on this.

So this starts around 745 and it's all the calls and pings on Holly's phones. And you take this and you determine where the tower is based on this first number up here.

So this starts around 745 and it's all the calls and pings on Holly's phones. And you take this and you determine where the tower is based on this first number up here.

This is the Bobo residence. The phone traveled north along this route, traveled about 32, 33 miles an hour north.

This is the Bobo residence. The phone traveled north along this route, traveled about 32, 33 miles an hour north.

FX presents Welcome to Wrexham. For the last four years, it's been this rollercoaster of magic. The Emmy Award-winning series returns.

All new Thursdays at 9 on FX. Stream on Hulu.

There was all kinds of leads coming in. We were looking at everybody. Everybody was looked at.

There was a point in the investigation to where the FBI agent and Dykus, the TBI agent, come up with a suspect. And who was that guy? That's Terry Britt.

We can map her phone to the minute. And that's exactly what I did.

Let's look at this map. Now this, this information, that is a cell dump of Holly's phone that morning. That means anything that Holly's phone registered on during that time is on this.

So this starts around 745 and it's all the calls and pings on Holly's phones. And you take this and you determine where the tower is based on this first number up here.

This is the Bobo residence. The phone traveled north along this route, traveled about 32, 33 miles an hour north.

There was all kinds of leads coming in. We were looking at everybody. Everybody was looked at.

There was all kinds of leads coming in. We were looking at everybody. Everybody was looked at.

There was a point in the investigation to where the FBI agent and Dykus, the TBI agent, come up with a suspect. And who was that guy? That's Terry Britt.

There was a point in the investigation to where the FBI agent and Dykus, the TBI agent, come up with a suspect. And who was that guy? That's Terry Britt.

We can map her phone to the minute. And that's exactly what I did.

We can map her phone to the minute. And that's exactly what I did.

Let's look at this map. Now this, this information, that is a cell dump of Holly's phone that morning. That means anything that Holly's phone registered on during that time is on this.

Let's look at this map. Now this, this information, that is a cell dump of Holly's phone that morning. That means anything that Holly's phone registered on during that time is on this.

So this starts around 745 and it's all the calls and pings on Holly's phones. And you take this and you determine where the tower is based on this first number up here.

So this starts around 745 and it's all the calls and pings on Holly's phones. And you take this and you determine where the tower is based on this first number up here.

This is the Bobo residence. The phone traveled north along this route, traveled about 32, 33 miles an hour north.

This is the Bobo residence. The phone traveled north along this route, traveled about 32, 33 miles an hour north.