Three care workers at Lancashire home care have been found guilty of abusing elderly residents.
The female staff members at Hillcroft nursing home in Slyne-with-Hest near Lancaster mocked, bullied and assaulted residents, Preston Crown Court heard.
A fourth male staff member earlier pleaded guilty to ill-treating the elderly residents.
The defendants told other staff they were bored and were doing it for entertainment, prosecutors said.
Carol Moore, 54, was the team leader of Ripon Avenue, Beaumont, Lancaster, she abused six residents including slapping one.
Tipped out of wheelchair, the abuse went this far, Gemma Pearson, 28, of Hill Street, Carnforth, tipped a resident out of a wheelchair.
Four residents were abused by Katie Cairns, 27, of Riverview Court, Westgate, Morecambe. She stamps on the foot of one, mocks others by throwing bean bags at them and touching them.
Darren Smith, 34, of Howgill Avenue, Lancaster, had previously pleaded guilty to ill-treating eight residents and the court heard he was seen in bed with a distressed resident.
Det Insp Andy Hulme said the staff members "showed a total disregard for their wellbeing, displaying contemptible behaviour that should never be tolerated".
Their actions "caused considerable distress to the victims, and it has been very distressing for their families to hear about it", the Crown Prosecution Service said.
Every one was charged under the Mental Capacity Act 2005 with ill-treatment and willful neglect of a person with lack of capacity.
The court heard that they had previously been suspended from the home following abuse allegations made by a receptionist and a cleaner in September 2011.
However they went back to work subsequent to being handed warnings as an effect of an internal investigation and the matter was not referred to the police or social services.
The Care Quality Commission (CQC) was sent anonymous emails about the standard of care inside the home, the court heard that in December 2011.
In May 2012, the CQC forwarded the matter to the local authority’s protection team who informed police.
In a statement, relatives of the victims criticized "failings" of managers at Hillcroft, Lancashire County Council, NHS North Lancashire and the CQC.
They also praised the courage of whistleblowers.
They said: "To work in a challenging behaviour unit must be incredibly difficult, requiring patience and understanding, not to mention training and professionalism, but the difficulty of the job does not excuse mistreatment on any level."
The home's owner said all those involved have now left and it is under new management.
The former staffs are due to be sentenced in January.