Erin Moriarty

But nothing had panned out.

And then, late on the evening of June 15, 2013, 911 dispatch received an anonymous call.

they transferred it to the Davis Police Department.

To determine if the caller was a crank or not, Corporal Scott Allen asked the person to share details about the crime.

And then he introduced the caller to Corporal Kirith Bresnik, who knew more about the continuing murder investigation.

The caller clearly knew a lot about the murders and had information that the police hadn't shared with the public or even the victim's family.

For weeks, the authorities have been looking at friends, family, anyone who had crossed paths with Claudia and Chip, trying to piece together who might have brutally murdered this beloved couple.

But what this caller revealed was beyond anything they had imagined.

The person the anonymous caller knew better than anyone else was named Daniel Marsh.

He was 15 years old.

I'm 48 Hours correspondent Erin Moriarty, and this is 15 Inside the Daniel Marsh Murders.

Episode 3, A Strange Tip.

After spending hours on the phone with police, the clearly nervous anonymous caller finally agreed to come down to the police station to talk in person.

The teenage tipster was Alvaro Garibay.

He arrived at the station early the following morning.

There, police led him into a small room and offered to grab him some snacks.

Alvaro was skinny, with long black hair that was pulled up into a ponytail.

He wore dark-framed glasses.

A camera in the room captured Alvaro as he nervously rubbed his hands together and tapped on the table next to him until the officers came back into the room.

At first, investigators weren't sure what to make of Alvaro's phoned-in tip.