Murder in Mexico of U.S. Resident. Mexican authorities are asking us to search deceased's residence. No indication of any crime having been committed in U.S. - Landlord will not open residence without search warrant. Any suggestions or reference material suggestions?

I don't know if you still need some help, but I was thinking you should ask the local PD or SO if there have been any 911 calls for his address. Or if it is a known crime location. Do the Mexican police think it's a drug related crime? If so, checking with your local law enforcement could give you some more info to get to probable cause. Sorry I didn't see this post sooner, and hope that helps.