A pensioner who died at a Manchester nursing home was "unlawfully killed", a coroner has ruled.
Ivan Emmanuel Campbell, 73, who had dementia, was a resident at Victoria Nursing Home in Rusholme when he died in April 2012.
He had suffered "catastrophic" abdominal injuries consistent with being "stamped upon or punched", the inquest heard.
Greater Manchester Police said it would be reviewing the findings.
Mr Campbell, who also suffered from type two diabetes, arrived in the UK from Jamaica in the early 1960s.
'Very heavy punches'
He had been a resident of the privately-run care home since June 2007.
The hearing at Manchester Civil Justice Centre heard how the former factory worker was about 5ft and weighed seven stone (44kg) at the time of his death.
Care worker Barry Delaney, 37, was arrested in 2013 on suspicion of the assault of Mr Campbell and another resident, 72.
He was released without charge, the hearing was told.
Mr Delaney had been working at the home on the night shift on 15 April 2012 and had checked on Mr Campbell at 02:00, 04:00 and 06:00 BST.
When the morning staff tried to wake Mr Campbell they found him "unresponsive".
The 73-year-old was taken to Manchester Royal Infirmary and died on 17 April.
Coroner Nigel Meadows said: "At no point has there been any evidence of a previous incident or circumstance where Mr Campbell could have possibly come to any significant harm.
"There were no falls and he was a resident on the ground floor. When I look at the evidence I'm satisfied that the only possible explanation is that Mr Campbell has been unlawfully assaulted."
'Upset, confused, angry'
Forensic pathologist Dr Philip Lumb told the hearing: "I think that it is very unlikely that it was an accident. It is very likely that this is an injury that is associated with physical assault.
"There was a split to the liver; it was a tear and almost divided the liver into two halves. We see these types of injuries from blows such as stamps, knees to the abdomen and very heavy punches.''
Following the ruling, Mr Campbell's three daughters said in a statement: ''We are just a mixture of emotions, everything possible, upset, confused, angry. But we knew this was going to happen - we knew someone had done it.
"We had been looking after our father for around five years before we put him in the nursing home. They were supposed to look after him, not kill him."
A month after Mr Campbell's death, the Care Quality Commission found "residents were not fully protected from effects of abuse or exploitation within the home" and there were problems with staff training.
In October 2012, inspectors said the home had improved and "now had effective systems in place to identify, assess, and manage risks to health, safety, and welfare".