Gun shot residue analysis please plese help!!!

Hello. can somebody please please help me on this? I am making my self ill and losing sleep. I have been searching for days trying to find the technique to analyse gun shot residues. I know one technique is SEM-EDX. BUT NEED SOMEBODY TO SHEDLIGHT ON HOW THIS ACTUALLY WORKS? what is the method for this? and is there any more techniques? thanks feel free to send me a private message if you know about this kind of stuff