Where a death is sudden or unexplained, the coroner will usually open an inquest. That is a separate process from a compensation claim, and its purpose is to establish who died and how, not to award anyone anything. Families often find it a demanding process, and it is worth knowing that you can be represented at it.
The evidence gathered for an inquest can be very useful in a civil claim, because it comes from witnesses and records that might otherwise be hard to obtain. Sometimes it is sensible to wait for the inquest to conclude before finalising the claim, and sometimes the claim can be started in parallel.
A criminal prosecution is also entirely separate. A civil claim can be brought whether or not anyone is charged, and whether or not any prosecution succeeds. If there is a prosecution, the timing of the civil claim may need to be considered carefully around it, and we will advise on that specifically. A decision not to prosecute does not prevent a claim, and neither does an acquittal.