Perhaps it's time to determine if this was really a self inflicted gunshot?
Sounds like a job for CSI... Is the residue on Juan's hands from shotgun powder, or from handgun ammo, or both...
"Now Mrs. Thompson, you said you were on the phone with your husband when he shot himself, but you aren`t sure if you heard the gunshot..Now how can this be, how can this be? You know my wife she makes a great lasagne, and sometimes when she calls me up, before we hang up we say I love you then goodbye. You never said how you ended that call with your husband."