The two women who murdered their best friend when they were teenagers are seen smiling in recent mugshots - and now the chilling tweets they sent after her death have been revealed.

Rachel Shoaf and Sheila Eddy, both now 23, of Morgantown, West Virginia, pleaded guilty to murdering 16-year-old Skylar Neese in July 2012.

Shoaf and Eddy, who were both 16 at the time, reportedly told investigators after confessing to the murder that they killed Neese because they simply didn't like her anymore, reported 20/20.

But in the 10 months between the stabbing and the girls being arrested, they remained active on social media and, in one tweet, referenced counting to three before murdering Neese.

Sheila Eddy (left) and Rachel Shoaf (right) smile in recent mugshots. The pair lured 16-year-old Skylar Neese from her home in July 2012 and stabbed her to death. After confessing to the murder, Shoaf said it was because they didn't like Neese anymore

The three girls were allegedly inseparable but tweets in the days leading up the murder indicate that the girls' friendship was strained. Pictured: Neese

Neese's parents, Dave and Mary, told 20/20 that the three girls used to go everywhere and do everything together.

But in the days before Neese was murdered, something changed.

On July 4, two days before she disappeared, she tweeted: 'It really doesn't take much to p***s me off' and 'Sick of being at f*****g home. Thanks "friends," love hanging out with you all too.'

And on July 5, just one day before her murder, she tweeted: 'you doing s*** like that is why I can NEVER completely trust you.'

Killers Rachel Shoaf (left) and Sheila Eddy (center) with their friend, and later victim Skylar Neese (right) in a Facebook photo

Neese's final tweet, sent out hours before she sneaked out of her apartment to meet her friends, was a retweet that read: 'All I do is hope.'

Mary Neese told 20/20 that Eddy told her the three of them had driven around town, smoked marijuana, and that they dropped Neese off by her apartment building.

Following the murder, Eddy kept up a steady stream of tweets. The first tweet came the day after the killing, on July 7, when she posted a happy birthday message to a friend.

She continued to tweet about watching her favorite TV shows, such as Law and Order SVU.

Following the murder, Eddy wrote several tweets including one that read: 'we really did go on three', a reference to how the girls counted to three before stabbing Neese

She also tweeted about how close her friendship was with Shoaf, writing: 'no one on this earth can handle me and rachel is you think you can you're wrong.'

Finally in January 2013, Shoaf confessed to investigators what she and Eddy had done and where the body was.

Eddy and Shoaf lured Neese to a secluded spot near the unincorporated West Virginia community of Macdale, where she was stabbed after they counted to three.

According to authorities, the girls covered Neese's body with branches after they had trouble burying her. Her body was discovered in a wooded area across the Pennsylvania border.

On March 30, 2013, Eddy tweeted 'we really did go on three.'

In May 2013, Eddy was arrested and Shoaf turned herself in. Both were tried as adults for murder.

In May 2013, Eddy (left) was arrested and Shoaf (right) turned herself in. Eddy was sentenced to life in prison and Shoaf was sentenced to 30 years

Neese's parents spearheaded Skylar's Law, which requires Amber Alerts to be issued in West Virginia for all missing children. Pictured: Davy and Mary Neese hold up a photo of their daughter, October 2012

Eddy pleaded guilty to first-degree murder and was sentenced in January 2014 to life in prison.

Shoaf pleaded guilty to second-degree murder and was sentenced to 30 years in prison in February.

Both are currently at the Lakin Correctional Center in West Virginia.

Since then, Neese's parents spearheaded Skylar's Law, which requires Amber Alerts to be issued in West Virginia for all missing children.