While the motives behind Robert Pickton's grisly crimes remain incomprehensible, freshly released police recordings may give the public some insight into the mind of Canada's worst-ever serial killer.

Two sets of recordings were unsealed on Friday, the most disturbing of which is video of a 2002 jail cell conversation Pickton had with his cellmate, who is actually an undercover agent.

In the conversation, shocking details emerge: Pickton talks about killing 49 women and says he would kill more, given the chance.

"I was gonna do one more, make it an even 50," Pickton tells the undercover officer. "Make it the big five-zero. (Expletive) half a hundred."

The tape also shows seemingly mundane details such as Pickton eating chili and passing a cup of coffee to his cellmate.

A separate audio tape was also released Friday: a police interrogation the day after Pickton was arrested. Earlier on Friday, the transcripts were made available.

The evidence was released after a court-ordered publication ban was lifted this week after Pickton's chances of appealing his case were dashed by the Supreme Court.

Pickton is serving a life sentence on six counts of second-degree murder. Given the Supreme Court's decision, the Crown stayed 20 additional murder charges as Pickton's sentence is already the longest under Canadian law.

At one point during the 11-hour police interrogation that took place in a small room in the Surrey, B.C. detachment of the RCMP, then-Sgt. Bill Fordy suggests Pickton's arrest had made him a national celebrity.

"You're bigger than the Pope, you're bigger than Princess Diana, you're just like f——-' (Osama) bin Laden. You know you're on the front page of every paper in the country today. Every one."

"In the paper?" Pickton asked.

"Everybody knows who you are right now," Fordy replied.

"In the paper today? They put me in the paper?" Pickton asked again, clearly unable to hide his growing excitement.

There is no question of the public's interest in Pickton's case, but the head of the B.C. Civil Liberties Union is reluctant to encourage people to view the tapes.

"I think it would be really unfortunate if we essentially lionized Robert Pickton and created a celebrity of him by focusing on the salacious details," David Eby told CTV News Channel.

Reporting from Vancouver, CTV's Janet Dirks says the tapes nevertheless provide insight into Pickton's character.

"At first, Pickton appears as a naive guy who doesn't seem to understand anything," Dirks said.

"But as the hours go by and they bring in a senior officer you see a different side of him. You see him put his feet up, he's cocky, he's sort of playing with their minds."

In the jail cell recording, Pickton later told the undercover officer that he was then going to kill another 25 women.

Although Pickton was portrayed by his defence as dimwitted, the former pig farmer appears to clearly understand his situation.

"They're going to nail me to the cross," he says more than once.

However, if Pickton initially claimed some responsibility for his murders, he now appears to hold the justice system in contempt.

This week, CTV's Jon Woodward spoke to Pickton by phone, and the former pig farmer complained that the justice system had failed him.

The killer said he resents his lawyers because they did not let him testify in his own defence, and he also insinuated that others may have taken part in his grisly crimes.

Evidence released after conviction upheld

The tapes' release comes after a longstanding publication ban was lifted after the Supreme Court of Canada upheld Pickton's conviction.

Pickton was first charged with murder in 2002 after police launched an exhaustive search of his pig farm in Port Coquitlam, B.C., about 30 kilometres east of Vancouver.

The three-year investigation ultimately uncovered the dismembered bodies, bones and DNA of more than two dozen women from Vancouver's Downtown Eastside.

Last week, Vancouver Police Deputy Chief Doug LePard publicly apologized for his department's failure to catch Pickton sooner.

"When faced with the worst, we should have been better," he said, acknowledging that there were indications a serial killer was at work.

Among the documents revealed to the public this week was the testimony of a woman who said Pickton took her to his farm in 1997, put her in handcuffs and tried to kill her. The two struggled in a knife fight that ended with both of them in hospital.

Pickton was charged with attempted murder, but the charges were stayed in 1998. That same year, a special team formed to review missing women files rejected the possibility of a serial killer hunting women in downtown Vancouver.

In 2001, the RCMP and the Vancouver police formed a joint task force to step up their investigation.

Pickton was arrested in February the following year. All the murders for which he was convicted occurred after the 1997 attack.

This week's revelations have stirred renewed calls for a public inquiry into the Pickton investigation. B.C. Premier Gordon Campbell said Thursday his cabinet would decide on the matter in the coming weeks.

Pickton is currently serving a life sentence for six counts of second-degree murder. With no chance of parole for 25 years, he is unlikely to ever be released.