This is on a 2000 Honda Civic DX hatchback.

Could it be the brakes? There is this weird squeaking that sound sort of like when the metal starts hitting metal with the brakes.

However, it's not a constant pitch. It sounds kind of like someone dying lol.

Any ideas?

 

Yes check the brake pads first. I know it sounds crazy but sometimes the brake squealers/indicators go off loudest and first only when backing up.