FxCop doesn't analyse source code, it works on .Net assemblies built from any language.
You may be able to find whether the method contains a statement or not using FxCop, I advice you to read the documentation and check the implementation of existing rules to understand it.
An empty statement in the middle of other code might be removed by the compiler and you may not find it using FxCop. If you want to analyze source code you should take a look at StyleCop.