
This episode covers the double homicide of Chip Northup and Claudia Mppen, the anonymous tip that led to the investigation, and the confession of Daniel Marsh.
Corporal Scott Allen and Corporal Kirath Breznik of the Davis Police Department receive an anonymous call on June 15, 2013, providing crucial details about the murders that had not been made public. The caller, later identified as Alvaro Garbe, reveals that Daniel Marsh, a 15-year-old boy, committed the brutal killings.
Alvaro recounts his friendship with Daniel, describing his troubled background and fascination with violence. He shares how Daniel confessed to him about the murders, detailing the gruesome acts he committed and his apparent enjoyment of the violence.
Despite initially being scared to report Daniel, Alvaro ultimately contacts the police after Daniel exhibits increasingly disturbing behavior. His testimony becomes a key piece of evidence in the investigation.
The episode concludes with Alvaro's interactions with law enforcement and the implications of his revelations about Daniel's actions leading up to the murders.
Alvaro Garbe reveals Daniel Marsh's confession about the brutal double homicide of Chip Northup and Claudia Mppen.

This episode stands out for the following:
He seemed very content and took a lot of pleasure out of it."Fifteen: A Strange Tip" | "48 Hours" Podcast (Episode 3)
I felt like throwing up, felt like I couldn't feel anything."Fifteen: A Strange Tip" | "48 Hours" Podcast (Episode 3)
I just need space, you know?"Fifteen: A Strange Tip" | "48 Hours" Podcast (Episode 3)
You cut both of them open just to see the insides or something."Fifteen: A Strange Tip" | "48 Hours" Podcast (Episode 3)
That's ridiculous. I'm a kid."Fifteen: A Strange Tip" | "48 Hours" Podcast (Episode 3)