Two things: First, you should consider contact the District Attorney's Victim Witness program. There may be some resources for you as the victim of a crime to help with the rent payment. Second, you should consider contacting the local Better Business Bureau for help dealing with Money Gram. My position is that when you deposited the money order in the drop box, you paid your rent and no further payment from you is required. The landlord may feel differently so you may need to negotiate a recovery payment plan that allows you to be reimbursed if the landlord is able to recover the stolen funds through an insurance or some other payment.
This is not a substitute for a consultation with a housing law attorney or housing advocacy organization in your community.
The issue is whether or not you "tendered" the rent to the landlord.
If the landlord merely leaves a box outside a door, you would know that this is really unsecured and you should know that if someone else takes that money, you may not be able to replace it. A moneygram is not quite like a check, or is it?
I thought a moneygram was made out to someone. If the banking institution didn't verify, maybe they could be held responsible.
If the box where you place your check is inside an area controlled by the landlord, I think you have a very strong case to show that you did pay the rent.
The issue here is who takes immediate responsibility for the rent payment? Police reports were filed. Based on the facts of this case, and whether the payment was tendered (based on control of the drop box and it's location), should be considered.
The landlord will probably make a big deal of not being paid. Therefore you may have to pay the rent again to avoid eviction proceedings and make claims against moneygram and the banking institution that cashed the check for the crooks. That is your best bet.
Also, if you have homeowner insurance, you may be able to make a claim against them, and the landlord's insurance company.
This is general legal advice intended for informational purposes only and does not create and attorney/client relationship. If you wish further advice, please contact an attorney of your own choosing or you may contact me for further advice and make other arrangements including retaining my services.