I wasn't referring to malicious intent like a bomb. I was referring to carrying out maintenance and not taking into account or ignoring the full implications. Surely that could be deemed then as manslaughter too and therefore is a criminal act, which the AAIB would have to report and hand the investigation over to the police. But I can't remember any case were this has happened before normally it has been a failure with maintenance procedures with a recommendation by the AAIB.
The police have only got about 3rd of the factual information, they obviously need to cross reference and check other statements from various parties, whom they may then wish to interview too. They do not have access to the supporting cockpit footage/audio nor have they had access to the aircraft and the ability/expertise to inspect it or the books.
Lets hope it is all settled in the next few months.