The twisted 16-year-old abducted Alesha from her bed before suffocating her and leaving her naked body in the woods on the Isle of Bute, Scotland, last year.
As the details of his crimes shocked the community, family, friends and well-meaning strangers posted emotive messages paying tribute to the girl.
One Facebook tribute, shared by a close friend of Alesha’s family, was reportedly “liked” by Campbell just hours after killed and brutalised her with 117 injuries.
His callous engagement with the post, which read “Alesha, always in our hearts”, has been described as “disturbing” and “calculated” by those aware of it.
One said his Facebook activity illustrates the “evil” nature of Campbell’s heinous crimes.
“It’s disgusting and disturbing that he would like the post just after Alesha was found dead,” a source told the Daily Record.
Another added: “This shows how calculated and evil he is.
“Imagine sitting watching the tributes flow in for the six-year-old girl he’d just raped and killed and then liking the post as if he was mourning for her like everyone else on the island.
“He’s an animal.”
“He’s an animal”
Campbell is facing a life sentence after he was found guilty of raping and murdering Alesha by a unanimous verdict at the High Court in Glasgow last Thursday.
Alesha, who was found naked, face down with her legs spread, sustained 117 injuries and died from significant pressure being applied to her face and neck, the court heard.
A disturbing picture of his personal life, including his obsession with fictional horror character Slenderman and love of playing gory and violent video games, has emerged as he awaits sentencing.
He could not previously be identified because he is under 18 but a judge unmasked him after a media campaign to remove his right to anonymity.
He could not previously be identified because he is under 18 but a judge ruled in favour of a media campaign to remove his right to anonymity.
A friend showed detectives messages Campbell sent her in 2017, saying he “might kill one day for the lifetime experience”.
According to his housekeeper mother, the fifth-year Rothesay Academy pupil was “clever at maths”, “well-liked” and had lots of friends.
Around 15 of these friends were at a party at his house on the night of July 1, before Alesha was killed.
As well telling the court he consumed a bottle of Mad Dog fortified wine and most of a bottle of Echo Falls wine that night, the trial heard he also used cannabis.
He had had a girlfriend for around a year while in his third year at school but was single in July last year.
He told the jury lies about how he would “never do something like that” when asked if he had killed Alesha.
Campbell also tried to convince the jury he had had sex with Ms McLachlan, the girlfriend of Alesha’s father, the night of the six-year-old’s murder.
He will be sentenced on March 21, when the court may hear more about his background and mental health.