The wheels of justice often grind slowly and sometimes they do stop completely and can't turn again in a particular case. True justice would be the victim being brought back, alive and well. There can never really be justice in a murder as a result. But just as often, even if a case is shelved for a few years, later it can be litigated. Different solicitor, different judge, people die and people retire. You just never know and there is no statute of limitations for murder.
If you believe in a higher power of some kind or Karma, then you might also believe each human is accountable for their actions in this life and harm done to others creates a Karmic debt that can't be escaped. Sometimes that is the only justice that will be found. Either way, the victim never comes back alive and that's really what all their loved ones want more than anything else.