Answer:
Tooth identification off the bite marks on the food. Maybe some dna off of it too.
Its a local team someone would have had to lnown the accounts so it was likely someone who was working there for long enough to be trusted. So if somone who was trusted to manage the accounts was missing it was prob them. Unless they're smart enough to be present and make other people around them look guilty. Like if you murdered someone and then blended into the crowd and looked at the murder scene because the cops would be looking for the person running away.