LEGAL experts described Halliwell's decision to defend himself as "extremely rare".

Already serving a life sentence after being convicted of the 2011 murder of Sian O'Callaghan, he was given access to legal texts in prison.

The unorthodox move has made the court process harder for his victims' families, according to Miss O'Callaghan's mother, Elaine Pickford.

Legal experts say it is highly unusual for high-profile murder defendants to represent themselves in the UK but it has been known in the US, where murderers including Ted Bundy have acted as their own legal counsel.

Barrister David Bentley QC, a criminal defence specialist from Doughty Street Chambers, said self-representation was unusual in crown court cases.

"It does happen. Certainly, in my experience, it is extremely rare," he said.

"There are many obvious drawbacks - first the complexity of a modern murder trial and managing the factual material and exhibits and so on.

"Normally on any serious murder case one would have a Queen's Counsel and a junior in court and a solicitor who would be preparing the case.

"And generally it's quite hard to remain objective about something you are in the middle of.

"You might get the jury's sympathy but you might end up alienating the jury. I cannot see how you would increase your chances of acquittal.

"You would not want to carry out surgery on yourself."

Solicitor James Turner, a criminal defence specialist for more than 20 years, said self-representation in serious cases was "ill-advised".

Elaine Pickford said Halliwell's decision showed no regard for either his victims' families or even his own.

But she said she was not intimidated by facing him in court.

"It's about control and he's doing it because he can and I don't think he has any thought for any of the victims, the families or even his own family, I think he's just about himself really," she said.

"I was surprised that for a crime of such enormity he was allowed to defend himself."