The family of Danny Fox say they “cannot comprehend” how two sets of jurors failed to reach a verdict on his killing.
Danny, 29, was stabbed in the neck by 21-year-old Leighton Holt, of Stockbridge Village, following a fracas in St Helens town centre last year.
However, Mr Holt claimed he was acting in self-defence.
Two juries failed to reach a verdict and he walked free from court.
Outside the court, Danny’s aunt Dawn Jones said: “We, the family of Daniel Fox, feel bitterly disappointed and let down with the outcome of the past two trials.
“We cannot comprehend how to sets of jurors could not reach a verdict over the killing of our precious son and nephew Daniel.
“We feel let down by what we see is failings in the justice system.
“We are considering our options as to what further action can be undertaken.
“We are also focusing our efforts over this in a positive way by starting a campaign to highlight knife crimes in our communities.” Dawn added: “We would like to thank Merseyside Police, in particular Detective Chief Inspector Chris Sephton and his team and family liaison officer Detective Constable Chris Haselden at St Helens for their hard work and continued support throughout this ordeal.
“Looking forward, we hope to prevent other families going through this horrendous nightmare and the life sentence that we are now living, without our much loved beautiful son and nephew Daniel.
“Danny didn’t deserve to die.
“Thank you to everyone for all your continued support and everybody in St Helens and beyond.”