I would definitely file a report with the RPA, they can deal directly with your former landlord. This is apparently becoming quite common among landlords who try to get out of paying their deposit, especially with tenants who have moved out. The most important thing here is for you to report the situation, in regard to your check, to your bank, which I hope you have done. A laborer who “finds” a blank check and then tries to deposit it is a thief, plain and simple. The bank should be able to trace the depositor through the number of the bank account into which the deposit had been attempted. Unfortunately, many laborers in California are illegal aliens – which is in itself a crime and many landlords do not verify the rights of a laborer to work in this country; and that in itself should be enforced. Hence, the check could have been deposited into a check cashing outlet, where it would be difficult to trace the person who committed the crime. It is important for all renters to know that tenants have a right to demand that they or a trusted person should be in the apartment whenever labor is being done. Landlords are required to notify a tenant whenever they have to enter an apartment, either by themselves or with laborers; and tenants have a right to monitor their apartment and their possessions. I hope this helps. Good luck to you.