Wildlife habits don't tend to be our area of expertise, but I can say from personal experience that a metal trash can with a bungee cord can usually do the trick. You can wrap or tie the bungy through the top handle on the lid, then hook it on the side handles of the main trash can. If it is lite enough where they can still tip it over, you could put a large rock or some bricks in the bottom.  Or you can search for wildlife-proof trash containers online or ask at a local hardware store. Bear-proof trash containers may seem like overkill, but raccoons can be quite dexterous with their little paws!  

Other then securing the trash better, we do believe there are better tactics to prevent them, but you can check with the Maryland Department Natural Resources. They link to this site: Wildlife Help or you can call them.

Good luck! 

Emily