Originally Posted by
Kulverstukas
Besides that Russian police investigates such possibility, it's greatly unlikely as it was return charter with mostly families aboard. Crew is highly unlikely too as it's small airline and staff is well paid in industry so rotation is quite small.
As was said earlier, a member of the cleaning crew would have found it easiest to plant the can, if the can was under a seat in the cabin and say up against the cabin wall. All the passenger searching is useless if the airside staff are compromised.