Skylar Neese Update: Teens killed 16-yr.-old W. Va. girl because "they didn't want to be friends with her anymore," victim's father says

(CBS/AP) STAR CITY, W. Va. - Rachel Shoaf, the 16-year-old who admitted murdering her friend, Skylar Neese, last summer, said she and another girl committed the crime because they didn't want to be friends with Skylar anymore, Skylar's father, Dave Neese, said in an interview with CNN. 

PICTURES: W. Va. teen allegedly killed by "friends"

Dave Neese calls the alleged motive "sick" and says he wants the girls charged in his daughter's death to "rot in hell."

"If you don't want to be friends with somebody, leave them alone. But, don't murder them," Dave Neese told CNN.

Skylar, 16, was initially thought to have run away after slipping out of her bedroom window in Star City, W. Va. on July 6, 2012. A break in the case didn't come until Jan. 3, 2013 when one of Neese's friends, Rachel Shoaf, admitted to authorities that she plotted with another girl to kill Skylar - and even told investigators where to find the body.

The two girls were charged with luring the straight-A student at University High School out of her family's apartment in the middle of the night, stabbing her to death at an agreed-upon moment and hiding her body under branches in a Pennsylvania township about 30 miles away from her house, according to court documents.

The pair had spent time with Neese's mother after the slaying and even helped with the search.

Shoaf, who was initially charged with first-degree murder, pleaded guilty to second-degree murder on May 1 as part of a plea deal and awaits sentencing in a juvenile detention center. According to court documents, prosecutors say they plan to recommend a 20-year prison sentence, but she could get up to 40 years under the law.

The other girl's identity is, for now, shrouded by the confidentiality of juvenile court. She is charged with first-degree murder, however it is unclear whether she will be charged as an adult, as Shoaf was.

Dave Neese told CNN the three girls were "inseparable."

"They were together all the time, especially the one that hasn't been named yet," Dave Neese told the station. "[Skylar] had just gotten back from vacation with her a week before this. She had been best friends with her since she was 8 years old. I mean, it's sick."

Complete coverage of Skylar Neese on Crimesider