Last night you were at the Smiths' house. There was a gun in your personal belongings, an object that could have a bad effect on your reputation (you always carry it with you).
You woke up in the night to a hysterical scream and ran out into the corridor: Ludwig and Anthony were standing next to Barbara by the bed at the scene of the crime. As an avid and experienced hunter, you looked at the wounds - the shot was clearly made by a non-professional (or a person who wants to make himself look like one).
During the time you worked with Henry, you happened to see Eric's work with your own eyes. The bullet went through his liver, the man was lying on the floor bleeding to death, and he just rolled up the car window and drove away without even checking the victim. All of Eric's shots were fatal.