Erin Moriarty

He didn't believe you?

So Alvaro kept his mouth shut and tried to go on with his life while police began investigating the murders.

But a few weeks later, Daniel approached him at school.

At that point, Alvaro had become scared of Daniel, fearful to be around him.

He knew that Daniel regularly carried a knife around, so he told a guidance counselor that Daniel had one at school.

Alvaro said that got Daniel expelled.

Afterwards, Daniel wasn't supposed to return to the campus.

But he did.

And while there, he approached Alvaro again.

Soon after, Alvaro was on the phone with Daniel's girlfriend, and suddenly she started panicking.

And that's when Alvaro grabbed a phone, called 911, and became that anonymous caller that you heard at the top of the episode.

Over the course of several more phone calls, he was eventually connected with Corporals Scott Allen and Kirith Bresnik.

Alvaro didn't want to give them his name, but eventually he became more comfortable and started calling Corporal Bresnik KB.

Alvaro spent hours with police in that interrogation room.

He told them about what Daniel had confessed to him about his actions on the weekend of April 13th.

It was the first real break in the case.

Investigators had closely guarded the details of Chip and Claudia's murders.

And now, inside that interrogation room, Alvaro was sharing gruesome details from the crime scene.

Alvaro had told the investigators everything he knew.

The police were going to allow him to go home, but first they wanted to try something.