Do you believe Ai parent death was accident ?
I don't think it was an accident (since accidents in mysteries rarely are what they're framed to be), but I'm not sure whether they commited suicide or whether they were killed as someone (like Vermouth) was trying to destroy all the research data.
If it's the former, then either a witness or Elena (through the recorded tape) is gonna have to reveal their suicide plan (maybe during Shiho's 19th birthday).
If it's the latter, then there will have to be a resolution with that person (i.e Vermouth), where we get the lab fire incident flashback through their perspective.






