Defenceless’ grandad, John Murray, 75, found beaten to death in his Chiswick home

John Murray, 75, died in Chiswick in October last year (Picture: Met Police)

The family of a grandad found dead at home have said they are ‘devastated and in complete shock’ after detectives launched a murder investigation.

John Murray, 75, died in Chiswick in October last year. A post-mortem held that month gave a cause of death as a head injury.

But a pathology examination later found it had been caused by an assault.

Mr Murray’s family said in a statement: ‘We are...