No, Direct Deposit in Germany usually refers to Giro[1] which is a payment between bank accounts. (Credit cards and even debit Visa/MasterCards are relatively uncommon in Germany)
I've never seen an actual cash deposit payment while I lived there, though we do have them in Sweden for example.
Seems like that should also open one up to an identifying attack of sorts. Find out when deposits were made (assuming there is more than one), grab all the security video from those times, and try to identify the person who is in all of those clips. Facial recognition software should get one the rest of the way. I imagine you would only need 3 or 4 deposit events to reliably identify someone?
I've never seen an actual cash deposit payment while I lived there, though we do have them in Sweden for example.
[1]: http://en.wikipedia.org/wiki/Giro