Five former staff members at a youth detention centre have been convicted over the physical abuse of young prisoners in the 1970s and 1980s.
The men, who are now aged in their 60s and 70s, worked at the former centre in Medomsley, near Consett, County Durham.
They were found guilty of a range of charges including assaults, wounding and misconduct in public office.
Jurors at Teesside Crown Court were told much of the violence was "for the enjoyment of the officers".
The five will be sentenced at a later date.
Their convictions follow a series of trials resulting from Operation Seabrook, which was launched by Durham Police in 2013 and became one of the largest investigations of its kind in the UK.
The guilty men are:
- Christopher Onslow, 72, convicted of inflicting grievous bodily harm, wounding and misconduct in public office. Acquitted of indecent assault
- John McGee, 74, convicted of assault occasioning actual bodily harm and misconduct in public office. Acquitted of sexual assault
- Brian Johnson Greenwell, 71, convicted of misconduct in public office. Acquitted of sexual assault and physical assault
- Kevin Blakely, 67, convicted of two counts of misconduct in public office. Acquitted of two counts of wounding and two of assault
- Alan Bramley, 70, convicted of misconduct in public office. Acquitted of wounding and two counts of assault
Two former officers were cleared of all charges:
- Neil Sowerby, 61, was acquitted of misconduct in public office, sexual assault and physical abuse
- David McClure, 63, was acquitted of misconduct in public office, wounding and four counts of assault
Onslow and McGee have submitted appeals against their convictions.
Medomsley, which closed in 1988, was built in 1960 to house offenders and at any one time held about 70 young men, aged from 17 to 21, detained for relatively minor crimes.
The aim was to keep them out of prison and away from the influence of older criminals, and its "short, sharp shock" regime was designed to deter them from a life of crime.
It was described as "demanding" but with a "background of discipline and control ... to develop personal relationships with the young men so they will be able to achieve a balance in their lives".
However, prosecutor Jamie Hill QC said there had been "an atmosphere of fear and violence throughout the institution".
Onslow, who was in charge of physical training between 1975 and 1985, exploited his position in a sadistic and brutal fashion, the court heard.
'Run on violence'
One victim suffered three crushed vertebrae when he fell 20ft (6m) from an obstacle course after Onslow threw rocks at him when he became stuck.
Another was beaten up by Onslow who said he lost a £10 bet when the 17-year-old lost a 200m race during a sports day event.
McGee punched one victim in the face, before forcing him to remove his underwear and "bunny-hop" to the showers when he had soiled himself.
Former inmate Eric Sampson likened it to a concentration camp, saying: "It was run on violence, every day, morning, afternoon and night."
Durham Police said 1,676 men had reported allegations of either sexual or physical assaults while detained at Medomsley and the investigation remains ongoing.
Det Ch Supt Adrian Green, who led the investigation, said: "We have worked hard to ensure victims and survivors are listened to and supported throughout the investigation and subsequent court process.
"We appreciate that for the victims and survivors of abuse at Medomsley Detention Centre, it has taken courage to come forward and tell police what happened to them."