The trial in Vancouver, Canada, of alleged serial killer Robert Pickton has been watching a key videotape made secretly in his jail cell.
Prosecutors allege Mr Pickton disposed of his victims on his farm
The police video shows pig farmer Robert Pickton in conversation with an undercover officer in the cell after he was arrested for two murders.
Mr Pickton tells the undercover officer he has been "set up" for 50 murders.
The 57-year-old has been charged with 26 murders but is initially being tried for six. He has pleaded not guilty.
Most of the women Mr Pickton is accused of murdering were prostitutes and drug addicts who disappeared from Vancouver's gritty Downtown Eastside during the 1990s.
'Nailed to the cross'
The videotape was made after Mr Pickton was arrested on 22 February 2002 in connection with two of the murders.
A Royal Canadian Mounted Police officer posing as a suspect for a violent crime was placed in his cell and their conversation was secretly videotaped.
"I'm screwed, tattooed, nailed to the cross, and now I'm a mass murderer," he told the officer.
The officer told the court he thought police wanted to charge him with 50 murders.
At the trial's opening three weeks ago, prosecutors told the court that Mr Pickton had admitted to the undercover officer to killing 49 women and that he wanted to kill one more to make it an "even 50".
Prosecutors allege that Mr Pickton butchered the women after he killed them and disposed of the remains on his pig farm outside Vancouver.
Police investigators spent months sifting through the farm collecting evidence.
A judge decided to split the case in two because the volume of forensic evidence collected from Mr Pickton's pig farm could have overwhelmed the jury.