A mother has been found guilty, with her partner, of murdering her two-year-old son and abusing two other children.
Rachel Trelfa, or Fee, 31, and Nyomi Fee, 28, were convicted of killing Liam Fee using "blunt force injury" that left him with internal injuries similar to those suffered by car crash victims.
A jury also found the pair guilty of a catalogue of cruelty towards Liam and two other boys over a two-year period in one of the most shocking cases of child abuse to come before the Scottish courts.
Their treatment of Liam, Trelfa's son, who turned up with injuries at two different nurseries, was repeatedly raised with social services. However, the explanations given for his injuries were accepted by the authorities.
The trial heard a senior child protection officer admit that at one point the family "dropped off the radar". The women claimed Liam had caused some injuries by pinching himself and said others were caused by a fall. A review of the way the authorities handled the tragic toddler's case has been announced.
Liam died from a rupture to his heart caused by blunt injury, but also had a broken leg and broken arm, which the women "treated" with Calpol instead of seeking medical help for him. The toddler had 30 separate injuries.
The women, originally from Ryton, Tyne and Wear, told police he had been killed at their flat near Glenrothes in Fife on March 22, 2014 by one of the other children and kept up the pretence throughout their trial.
Much of the crucial evidence in the case came from interviews conducted with the two young boys. The couple faced eight separate charges containing horrific allegations.
They assaulted Liam between March 15-22, 2014, as well as on various occasions between January 2012 and March 2014. His weight when he died was not only low for his age, but lower than it had been eight months previously.
Over the same period, the sadistic pair assaulted two other boys, who cannot be named for legal reasons, making one stand naked under a cold shower for lengthy periods as a punishment for wetting the bed.
They also forced him to stay for long periods, naked or in his underwear, in a cage made from a metal fire guard and pieces of wood.
The neglect charge against the second child involved 20 allegations, including threatening to cut off his penis with a saw. They were said to have deprived him of food and tied him naked to a chair in a room where they kept rats, snakes and a boa constrictor, which they said ate "naughty boys".
After the tragedy, Scottish SPCA officers removed nine snakes, a family of rats and two dogs from the three-bedroom property in Thornton, near Glenrothes.
The court also heard a pet shop owner claim she bought two snakes from the couple on the day Liam died.
Trelfa was living with Liam's father, Joseph Johnson, when she began an affair with Nyomi Fee in Ryton, outside Newcastle, in 2010. When she became pregnant with Liam they moved to Scotland and entered a civil partnership in June 2012.
The handling of Liam's case by the authorities will be the subject of a significant case review (SCR) chaired by Dr Jacqui Mok, a retired paediatrician and child protection specialist.
She will review all records and interview staff involved in the circumstances leading up to the toddler's death.
Douglas Dunlop, vice-chair of Fife's Child Protection Committee, which represents the local authority, police, NHS, and the voluntary sector, said the review would establish if their were lessons to be learned, adding: "I know it was said in court that there was a break in contact from a specific team in relation to Liam and other services continued to be involved with him during that period."