It used to be standard practice that whenever a death occurred due to homicide, whether criminal, justified, accidental, or neglectful, it would always result in a Medical Examiner inquest and a Grand Jury investigation.
This was not a bad idea, but in both cases, the insistence of full, formal hearings in all cases became cost prohibitive, yet instead of streamlining and making these cases more efficient, it was decided to not do them unless there was an obvious need.
Today, things are so bad that in many cases, Coroners only perform ‘pro forma’ autopsies, and families are hiring private medical examiners to remove any doubts as to state of health and cause of death.
There is not yet a private equivalent of a grand jury, but eventually someone might devise one, with the idea of providing its conclusions to the appropriate prosecutor to help them determine that an official Grand Jury should be convened.
To my understanding, that was the original intent in both British and American jurisprudence. A Citizen would present his complaint and evidence directly, and if the GJ agreed they forwarded a Bill of Particulars to the District Attorney. That the DA's and Courts have usurped that provision is one of the reasons victims receive little justice in our current system.
Make it so the Complainant has to foot the costs if the GJ issues a "No Bill" and will cut out the frivolous suits, both criminal and civil. 'Loser Pays' is a good idea that should be implemented across the board.