Killer Christa Pike to be executed within days - but her defence say she's a victim too

Ashlee Sellars last heard from her friend Christa Pike earlier this week, when Pike texted her from her cell on death row as she prepares to be killed by lethal injection by the US state of Tennessee.

Pike told Sellars she did not want any of her loved ones to be present on Wednesday when she is executed.

Sellars finds it hard to reconcile this woman, whom she has only known to be kind and protective, with the person who committed a heinous crime 31 years ago.

Pike, now 50, was 18 when she and her boyfriend at the time, Tadaryl Shipp, beat, tortured and murdered Colleen Slemmer, a 19-year-old they met at a job training camp for troubled teens.

The murder created a media frenzy in Knoxville, Tennessee in 1995, when Colleen was found with a pentagram - a symbol of Satanic ritual - carved into her chest.

Pike had accused Colleen of insulting her and trying to steal her boyfriend. Two other residents at the camp later testified that Pike had bragged about the murder before and after, and showed them a piece of Colleen's skull.

A year later she was sentenced to death, while Shipp - who was 17 at the time - was given a life sentence with the possibility of parole.

Now, after years of failed appeals, Pike's execution has been set. If it goes ahead, she will be the first woman put to death in Tennessee in more than 200 years. Only 18 women have been executed in the US since the 1970s, compared to 1,663 men.