What did Campbell claim about the murder?
After police were led to Campbell by his own mum, the monster told various lies about what he did on the night Alesha vanished.
Sickeningly, he even tried to blame Mr MacPhail's innocent partner, Toni McLachlan, for the crime and claimed he'd had an affair with her.
On his trial's first day, he lodged a special defence of incrimination, naming Ms McLachlan as the person responsible for the killing.
However, jurors heard DNA matching Campbell was "pretty well all over" Alesha's body and clothes, and he had told police "a pack of lies".
Giving evidence in court himself, the teenager told the jury he'd "never do something like that" in reference to the attack last summer.
He claimed that he "never met Alesha MacPhail in person".
Asked if he "brutalised" the girl, he said: "It's not me, absolutely not.
"I would never do something like that."
But when jurors were out of the courtroom, he is said to have been spotted smirking.
The teenager, described as an 'adrenaline junkie', also told the court he and Ms McLachlan had met up and had sex early on July 2.
He claimed he did not want to tell police this as he feared it would get back to Mr MacPhail and he would "hurt" Ms McLachlan.
But addressing the jury on Wednesday, advocate depute Iain McSporran QC, prosecuting, said the teenager was telling "a pack of lies then [to the police] and a pack of lies in the witness box".
During his closing speech, Mr McSporran put it to jurors that they had heard no evidence implicating Ms McLachlan in the crime but a "mountain of evidence" linking the accused to it.
He also said a claim by Campbell - that Ms McLachlan had taken the condom the two allegedly used on July 2, gone back to the house where she had been staying with her partner, Alesha and the girl's grandparents, abducted the schoolgirl, carried her to the woods, smothered her to death and then planted the accused's semen inside her - was a "preposterous story".
However, the teenager's defence lawyer, Brian McConnachie QC, urged the jury to acquit his client, questioning why he would abduct, rape and murder the youngster having "never met her in his life".
All we know about Alesha MacPhail's smirking teen killer Aaron Campbell