The chilling video has been presented as evidence. Photo / Supplied
The video shows the teenage couple cuddled together, the picture of innocent, young love.
Until the smiling young man says to the camera: "Welcome back to our YouTube channel. Day 3 after murdering somebody."
"Whoa!," his giggling girlfriend says. "Don't put that on camera."
"It was worth it," he replies, squeezing her throat until she gasps.
Prosecutors allege that the chilling claim was no idle boast and that 18-year-old Aaron Guerrero and 16-year-old Sierra Halseth had murdered her father just days earlier after he disapproved of their relationship.
The video was recently released by a court in the US state of Nevada, which is hearing charges of murder against the pair in connection with the death of Halseth's father, Daniel Halseth.
Halseth's body was found at his Las Vegas home on April 9, after he was reported missing.
Las Vegas Metropolitan Police Department homicide detective Matthew Hocking told the court that Halseth has been stabbed multiple times before he was stuffed inside a sleeping bag and set on fire.
Police also found a chainsaw, circular saw, handsaw and large bottles of lighter fluid at the property.
Surveillance footage from nearby hardware stores showed Guerrero and Halseth buying the items.
The Las Vegas Review-Journal reported that the young couple had been together for seven months but had been split apart by their parents after their plan to run away to Los Angeles was discovered.
After the brutal killing, the couple allegedly fled the state before they were picked up in Utah while trying to board a train.
It was then that police discovered the incriminating video on Sierra Halseth's phone.
The pair are yet to enter a plea.
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