Nicole McGregor, 31, was found in parkland in Leamington Spa, Warwick, on October 29.
The mum-of-three's death is being linked to the murders of Julie Williams, 58, and her son, David Williams, 32.
Their bodies were found at separate flats in Coventry on October 25 and 26.
Anthony Russell, 38, has been charged with three murders as well as robbery in connection with a car-jacking of a red Ford C-Max.
It has now emerged that Miss McGregor, who lived in Leamington Spa, was facing prison for drug dealing when she was killed.
On October 14, just days before her murder, she appeared at Coventry Magistrates' Court and admitted possessing heroin with intent to supply.
She also pleaded guilty to possessing a bladed article and was bailed before her sentencing hearing on Tuesday.
Warwick Crown Court heard she was facing a four-and-a-half year prison sentence for the offences.
Judge Sylvia de Bertodano reprimanded prosecutors for failing to provide the court with Miss McGregor's death certificate.
She said: "The reason I am surprised is that it is my understanding that Miss McGregor was the unfortunate young lady who was murdered last month."A suspect has been arrested in respect of that, and I was expecting you to come armed with a death certificate."I find in this case that there is, on the face of it, evidence that the defendant has died since she indicated her guilty plea.
"Therefore the correct course of action is to adjourn proceedings without a date. The proceedings are effectively at an end."
Speaking after her murder, Miss McGregor's twin brother Adam paid tribute to his "beautiful twinnie".
Writing on Facebook, he said: "Words can't even express how I'm feeling at the minute.
"For the first time in my life I'm afraid of being alone more then ever.
"Fly high high darling twin. RIP twinnie look and watch over us all. Until we meet again."
Miss McGregor had previously gushed over her three kids, saying she was the "proudest mum in the world".