Children jailed for first-time petty offences
He ordered children as young as 8 to be detained for first-time offences like petty theft, jaywalking, truancy and smoking on school grounds.
Some of them were immediately handcuffed and shackled and led away, without being given a chance to say goodbye to their families.
In his civil ruling, US District Judge Christopher Conner awarded US$106m in compensation to the victims.
That was partly based on a figure of US$1000 for each day of wrongful detention.
He also awarded US$100m ($188m) in punitive damages to nearly 300 people, who he said were "the tragic human casualties of a scandal of epic proportions".
Former judges 'cruel and despicable'
The judge said: "Ciavarella and Conahan abandoned their oath and breached the public trust. Their cruel and despicable actions victimised a vulnerable population of young people, many of whom were suffering from emotional issues and mental health concerns."
Several victims who were part of the civil case when it began in 2009 have since died from drug overdoses or suicide.
Ciavarella, 72, is serving a 28-year prison sentence in Kentucky and is not expected to be released until 2035.
Conahan, 70, was sentenced to more than 17 years in prison but was released to home confinement in 2020.
In the civil case last year the court heard emotional evidence from 282 people who appeared in Luzerne County juvenile court in Pennsylvania between 2003 and 2008.
Of those, 79 were aged under 13 when they were sent to juvenile detention.
One unnamed child victim testified that Ciavarella had "ruined my life" and "just didn't let me get to my future".
Another said: "I feel I was just sold out for no reason. Like everybody just stood in line to be sold."
In his ruling Judge Conner said: "They [the victims] recounted his [Ciavarella's] harsh and arbitrary nature, his disdain for due process, his extraordinary abruptness, and his cavalier and boorish behaviour in the courtroom."
In the wake of the scandal the Pennsylvania Supreme Court threw out 4000 juvenile convictions, involving more than 2300 defendants.
Lawyers for the victims said they did not expect to receive the damages, but said the amount awarded showed the enormity of the former judges' crimes.
Marsha Levick of the Juvenile Law Centre, representing the victims, said: "It's a huge victory. To have an order from a federal court that recognises the gravity of what the judges did to these children, in the midst of some of the most critical years of their childhood and development, matters enormously, whether or not the money gets paid."