One of Scotland’s top prosecutors has admitted he was left “completely confounded” by the 16-year-old boy who raped and killed Alesha MacPhail.

Iain McSporran QC led the case against Aaron Campbell, who was locked up for at least 27 years at the High Court in Glasgow last March.

Campbell snatched the six-year-old from her home on the Isle of Bute and left her body in woods after his attack.

Recalling the “horror” of the case in a video with the Hey Legal online platform, the 56-year-old QC described it as his “most memorable for all the negative reasons”.

Mr McSporran said: “I will never be able to rid myself of the feelings I have from that case and I’m sure I’m not alone.

“All the police officers, even the pathologist giving evidence was almost in tears, the defence counsel and an agent I know, all were affected and will be affected by that case.

“You think you’re immune to it, but you’re not – every time I see a newspaper article or something on the television about the case and I see the photograph of that beautiful wee girl, it just takes me back to the most horrible place.

“Perhaps a selfish thing about that case is that despite thinking I have a reasonably good examination style, I have to acknowledge that I was completely confounded by a 16-year-old boy.

“It makes you think what skill set do I have if he was able to resist my apparent skills – but that’s a selfish and trivial thing.”

Mr McSporran also discussed another case he took for the Crown against Edward Cairney and Avril Jones, who murdered “friendless and lonely” Margaret Fleming almost two decades ago.

At the time he told the court the pair “literally got away with murder for 16 years” before last summer they were sentenced to life imprisonment with a minimum term of 14 years each.

The case then became the subject of a television documentary which Mr McSporran said made it memorable “simply because I have a permanent record of it”.

He added: “That was an interesting programme to participate in – I’d loved to have seen more episodes because I know they filmed a lot more with me in the court and other participants.

“Being able to see that on television and see the good reaction it got generally… the excellent work of everyone in the criminal justice system I think came out of that very well with a very good reputation.

“Everyone involved – the judge, defence counsel – could have contributed to making that a good advert for the Scottish criminal justice system and the filmmakers did a good job.

“People still say to me in the street, ‘Were you the guy from the TV?’ and generally they say, ‘We thought it was brilliant’.

“I think the public got a good insight… even though there’s the sadness of Margaret Fleming.”