After a three-year review of 200 patient deaths by five detectives, Staffordshire Police says there were 'no grounds' to criminally charge hospital bosses or staff.
Ron Street, aged 81, of Hednesford, was a long-time friend and carer of diabetic Gillian Astbury who died at Stafford Hospital aged 66 when nurses failed to give her insulin.
Mid Staffordshire Foundation Trust was fined £200,000 in the first case of its kind in 2014 after the trust pleaded guilty to health and safety failings over her death brought by the Health and Safety Executive (HSE).
Mr Street feels the trust's admission in Ms Astbury's case and later four other deaths, is enough evidence to prosecute individual bosses.
He said today: "It sticks in my craw that not one individual or individuals are being held to account."
John Moore-Robinson, aged 20, died in April 2006 after medics failed to spot his ruptured spleen following a mountain bike accident on Cannock Chase.
His father Frank Robinson, from Leicestershire, said: "The management and staff responsible for John's death were not held accountable and never will be – and we've got to live with that. The review is a non event which told us nothing new, all the villains escaped justice."
The review looked at 214 deaths between 2005 and 2009 in the wake of the damning Francis Inquiry that found hundreds of patients suffered poor care.
Police say without the review that successful HSE prosecutions of the former Mid Staffs trust over the deaths of Ms Astbury, Ivy Bunn, 90, and Lillian Tucker, 77, would have been 'highly unlikely'.
The trust was fined £700,000 across two prosecutions of five patient deaths.
Stafford Borough Council leader Patrick Farrington said: "People will of course be upset and disappointed."
George Adamson, leader of Cannock Chase Council, said: "Someone should be taking responsibility for what has happened."
Deputy Chief Constable Nicholas Baker said: "Staffordshire police acknowledges nothing can mitigate the loss and subsequent distress the families have suffered during what must have been an extremely traumatic time."
A HSE spokeswoman said: "We did not find sufficient evidence to take action against individuals."