A multi-agency learning review of the handling of the case will now be carried out to look at the circumstances of the four children involved, who were all aged under 13.
Iain Owens, 45, Elaine Lannery, 39, Scott Forbes, 50, Barry Watson, 47, Lesley Ann Williams, 41, Paul Brannan, 41, and John Clark, 47, were convicted of sex abuse following the trial, while Marianne Gallagher, 38, was convicted of assault.
Detective Superintendent Nicola Kilbane said officers followed up more than 1000 lines of inquiry and police workers were offered support following the “harrowing” evidence.
She said: “The levels of depravity shown in this case were extremely rare in Scotland and the courage of the victims was essential in ensuring these convictions.
“This was a long, complex and challenging investigation for a team of offices and staff who have had to work through the most harrowing evidence to bring those responsible for these crimes to justice.
“We remain committed to supporting victims of sexual crime and protecting children from harm and abuse.”
Ms Kilbane then urged any victim of abuse to approach police and ask for support.
Judge Lord Beckett had described the case as “the depths of human depravity” and said the evidence heard had been “harrowing”.
Owens, Lannery, Williams, Brannan, Forbes, Watson and Clark were all convicted of a string of sex crimes towards children including rape and sexual abuse in a Glasgow drug den where heroin and crack cocaine were used.
Four of the group – Owens, Lannery, Brannan and Williams – were found guilty of attempting to murder a child by pushing her into a microwave and trapping her in various places including a cupboard.
An eighth person – Marianne Gallagher, 38 – was found guilty of assaulting a child and was granted bail.
Three of those on trial at the High Court in Glasgow – Mark Carr, 49, Richard Gachagan, 46, and Leona Laing, 51 – were acquitted of all charges.
Owens, Lannery, Brannan, Williams, Forbes, Watson and Clark were found guilty of taking part in the gang rape of a child.
The offences, involving four children, happened between 2012 and 2019.
Police launched an investigation in June 2019, and arrests were made in October 2020, but it emerged two of the child witnesses were questioned around 40 times during the investigation, prompting a review of the case.
Ms Kilbane said specialist officers were with the children throughout the police enquiry but would not be drawn further, in light of the impending review.
She added that the case was “absolutely like nothing we had come across before” and pledged to use all available resources to get convictions in any future such cases.
Colin Anderson, independent chairman of Glasgow’s Child Protection Committee, said: “This has been a highly complex case.
“The circumstances of the children involved will be subject to a Case Learning Review, in accordance with the Scottish Government National Guidance for Child Protection Committees Undertaking Learning Reviews.
“It is therefore inappropriate to comment further at this time.”
During the trial, the Crown said it would have been “off-the-scale devious” to concoct the allegations.
An allegation that the accused used a Ouija board to “call on spirits and demons” causing the child victims to “believe that they could see, hear and communicate with spirits and demons” and making them take part in “witchcraft”, was dropped by prosecutors during the trial.
Iain Owens, 45, and Elaine Lannery, 39, were both convicted of attempted murder and multiple counts of assault, sexual assault, rape and causing a child to ingest drugs and alcohol.
Lesley Williams, 41, was convicted of attempted murder, assault, rape and supplying drugs.
Paul Brannan, 41, was convicted of attempted murder, sexual assault, causing children to consume drugs and alcohol, rape and supplying class A drugs.
Scott Forbes, 50, was found guilty of rape, while Barry Watson, 47, was found guilty of rape and sexual assault, and John Clark, 46, was found guilty of rape and sexual assault.
All 11 of those who stood trial were acquitted of killing dogs.
In discharging the jury, Lord Beckett thanked them for their “remarkable public service”.
He said that given their “extraordinary service”, he is excusing each of them from ever again serving on a jury.
“It has been a very difficult trial to listen to,” Lord Beckett added.
“It has been pretty unpleasant and shocking.
“It plunges to the depths of human depravity.”
Owens, Lannery, Williams, Brannan, Forbes, Watson and Clark will be placed on the sex offenders register, but the length of this will be determined at sentencing.
Lord Beckett remanded the seven in custody and adjourned the case until January 4 for reports and sentencing.
Three others were acquitted of charges.
Mary Glasgow, chief executive of Children 1st, Scotland’s national children’s charity said: “The depth of trauma that the children, in this case, have suffered will be unimaginable to most of us.