'Mean Girl Murders': Christa Pike killed rival in high school love triangle, took piece of her skull: doc

Christa Pike, who earned her spot as Tennessee's only female death row inmate by stabbing and beating her classmate to death – then nearly executing an elaborate prison break – was featured on a recent episode of Investigation Discovery's "Mean Girl Murders."

Now 48, Pike was convicted in 1995 for killing fellow Knoxville Job Corps computer programming student Colleen Slemmer, who was 19 at the time. The murder was carried out because Pike believed Slemmer wanted to "steal" her boyfriend.