The defendants had spent months leaving a false trail for detectives before the murder, creating fake profiles for Miss Wells-Burr on adult websites and sending texts to her phone from a supposed mystery lover.
Business graduate used a number of social networking websites and at first Nowak and Lagwinowicz had attempted to lure the 23-year-old into flirting with other men, by targeting her accounts with suggestive messages.
But their plan was thwarted when Catherine either ignored the messages or replied "I have a boyfriend, leave me alone".
The killers instead launched a number of fake profiles for Miss Wells-Burr to leave a false trail for officers investigating after her death.
After their arrest Anna Lagwinowicz made another attempt to cover her tracks from prison, attempting to send a fake anonymous letter to prosecutors that claimed Rafal Nowak had first tried to hire a hit man to kill her.
When this failed, the letter stated, he decided to murder Miss Wells-Burr instead and plant evidence to point the death squarely at Lagwinowicz's hands.
However her scheme backfired when prosecutors were told by her cell mate about the letter and instead used details contained in the note to compile further evidence for her prosecution.
More top news
Authorities have warned that the death toll is likely to rise as much of the building is yet to be searched.
The PM will sound out the possibility of new free trade agreements with Gulf states for once the UK has left the EU.
In the unexpected announcement on Monday, Mr Key said it was the "right time" to leave politics.