Accused Canadian serial killer Robert "Willie" Pickton, talked with an undercover police officer about wanting to kill as many as 75 people.
The jury at his trail heard the comment on a secretly videotaped conversation in which a relaxed looking Mr Pickton also talked about using a rendering plant to dispose of bodies and of toying with investigators in the case.
Prosecutors have not described the comments as a confession.
Mr Pickton has pleaded not guilty to 26 charges of murder though this trial deals with only six of the charges.
In the often rambling conversation recorded in a jail cell shortly after his arrest in 2002, Mr Pickton first signals with his hands to an undercover officer posing as an inmate that he wanted to kill one more victim to make his total 50.
"I wanted one more, make, make the big five-O," he says later.
After complaining he had attracted police attention by getting "sloppy" in disposing of evidence, Pickton said he planned to "let everything die for a while ... then do, do another twenty-five new ones."
The women Pickton was accused of killing were among more than 60 missing Vancouver women, whose disappearances were the focus of a major police investigation at the time of his arrest.
Police say Mr Pickton now 57, lured drug addicts and prostitutes to his pig farm in Port Coquitlam, British Columbia, near Vancouver.
There, police say, he killed them, butchered their bodies and then disposed of the remains both on the property and at an animal waste rendering plant.
Mr Pickton's conversation with the undercover officer came after he had completed a nearly 11-hour formal police interrogation - a recording of which has already been played for the jury of seven men and five women.
In that interview, Mr Pickton initially denies knowing anything about the missing women, but later suggests he would be willing to tell police about the killings if they agree to stop searching his farm.
"I had them going. I had them going," he tells the officer - who cannot be identified because of a court publication ban.
Mr Pickton's lawyers have said police tried to trick him by lying about the amount of evidence against him, and that he was very tired at the end of the interrogation and might not have known what he was saying.