I get what you're saying here and having empathy and compassion for the victim and his/her family, it would seem to be the right thing to do, however, there always seems to be an ulterior motive. Nowadays you can't trust which direction the conversation will go and what that conversation will end up doing to alter your own future. That whole "can and will be used against you" thing.So I’m confused here, did you do something wrong? Myself, I wouldn’t hesitate to help with a homicide investigation unless the investigator was being a complete dick. The idea that some monkey ass fool went and committed murder with the firearm I sold him is on him not me.
Should say absolutely nothing unless subpoenaed and if that happens the conversation needs to be in the company of a lawyer.