The police will be acting effectively as agents of the AAIB and coroner in this case. They will have the experience and resources to assist in gathering evidence from scene, witnesses and recorded media. They will very much be led in this by the AAIB.
When we're talking about prosecutions it's probably worth looking at the ongoing Glasgow bin lorry crash.
Don't mix up offences with crimes either. Not everything that is an offence is a crime. Drink driving being an example.