If an accused felt he had information that perhaps LE was not following up on, wouldn't his lawyer be able to follow up on it through a PI, as part of the accused's defence and include it in his legal bill? I'm not sure how the legal aid bill is presented, how specifically it might be itemized for how the amount accrued to whatever the total ends up being? Why would legal aid provide money for a serial murderer to have a defence team of 7 lawyers, paid for with the public purse?
Why would legal aid provide money for a private investigator? That's not part of a normal defence.