7am January 27, 2016. US mother Tammy Lovell phones police in a panic. She’d woken to find her 13-year-old daughter Nicole’s bedroom door barricaded shut, her window open and her bed empty.

That evening, as local media reports about the missing teenager began to mount, two students from Virginia Tech university stroll into a Walmart supermarket. They purchase a small amount of cleaning supplies – bleach, wipes and rubber gloves – and drive away.

In the boot of that sedan lies Nicole Lovell, dead.

The teenager’s body was discovered on January 30 near Highway 89 in North Carolina, roughly three kilometres across the border from her home state of Virginia, The Roanoke Times reported. Stabbed 14 times. Stripped naked. Wiped down with bleach. Dumped.

David Eisenhauer, then 19, had been arrested earlier that day for abduction, after investigators looked into Nicole's social media activity.

The young girl, who dreamed of being on American Idol, who loved pandas and dancing and the colour blue, had struck up a relationship with the engineering student. They'd been chatting online for months and met in person at least once, according to CBS.

Fearing their relationship would come to light, David enlisted the help of his friend Natalie Keepers, also then 19, to devise a final, fatal plan to protect himself.

Messages on the app KIK showed them plotting possible methods, including swapping Nicole's medication for cyanide pills. GPS data from David's car showed them scouting the location, and CCTV footage from a Walmart supermarket captured them purchasing a shovel. All in the day before her murder.

Thanks largely to testimony provided by Natalie after David's arrest, it was revealed that he had picked up Nicole from her home on January 26 under the guise of taking her on a date, driven to nearby woodland and stabbed her to death. Nervous about growing media attention, he and Natalie then moved the body to North Carolina the following day.

Police later found Natalie's bloodied handprint on the handle of the shovel. Blood was also found on her boots, and in a search of her college dorm room, investigators uncovered Nicole's blood-stained Minion blanket stuffed inside a gym bag.

David was sentenced to 50 years in prison for first-degree murder in June. Natalie pleaded guilty to concealing a body, but fought an accessory charge.

She told police she was not present for the killing, and that she didn't actually believe Eisenhauer would go through with it.

Choking back tears, she pleaded with the jury.

"I'm so sorry. Words can't express how sorry I am. I never intended for this to happen," she said, according to The Roanoke Times.

The jury didn't buy it. On Friday, after less than 90 minutes of deliberation, they convicted the 21-year-old over her role in the plot, NBC reported. They recommended a 40-year sentence, which will be considered by a judge in November.

Following the verdict, Montgomery County Commonwealth's Attorney Mary Pettitt said he wished he could wave "a magic wand" and bring Nicole back, according to local media.

"None of us are able to do that, unfortunately," she said. "The best that I really can do is the stare evil in the face, speak for the dead and hope I can get justice for them."