No Bedfordshire police officers will be charged over the death of a man in custody, the Crown Prosecution Service (CPS) has said.
Leon Briggs, 39, died in hospital on 4 November 2013 after becoming ill at Luton police station.
In March, the CPS had said there was "no realistic prospect" of convicting one officer.
It has now said it will take no further action against four other officers and a member of police staff.
Justice for Leon, a campaign group consisting of Mr Briggs' family and friends, called the decision "scandalous".
A statement from the group said: "In light of the disgraceful, wicked and sadly expected decision by the police and the 'justice system' that protects them to disrespect, disregard and insult the memory of Leon Briggs and his grieving family, the Justice for Leon campaign is today changing our title to Justice for Luton.
The group said it would consult with lawyers and "use all legal means necessary" to reverse the "unjust decision".
Mr Briggs, from Luton, was being held under section 136 of the Mental Health Act following concerns about his behaviour on Marsh Road, Luton.
Section 136 of the Mental Health Act gives police the power to take a person of concern from a public place to a place of safety.
Mr Briggs was placed in a cell at the station and restrained. He later became ill and was taken to hospital where he was pronounced dead.
The Independent Police Complaints Commission, as it was called at the time, referred the case to the CPS in 2016 after it found there was "an indication" that five officers and a member of staff "may have committed criminal offences".
'No further action'
A CPS spokesman said that after its decision in March, it had "now examined the evidence against the remaining individuals and the force itself and concluded our test for bringing a prosecution is not met".
"As a result we will not be taking any further action in this case," a statement said.
Mr Briggs' mother Margaret said she was "devastated" by the decision.
"My son was struggling with his mental health, that struggle should not have resulted in his death at the hands of Bedfordshire police," she said.
"My one hope is that the inquest into Leon's death can start as soon as possible. I am desperate for some answers and hopefully, in time, some closure."
Bedfordshire's chief constable, Jon Boutcher, said: "It has taken almost five years to reach this position and that is simply unacceptable for all concerned.
"The time taken has put added strain on Mr Briggs' family, and, please let us not forget, the officers involved."
He added that the force continues to look at how it can improve its knowledge of and response to dealing with vulnerable people.