You are mistaken on both counts.
People have been prosecuted for killing burglars. It is illegal in most instances to use excessive force to prevent a non-violent crime. In some states, there are protections for someone killing a burglar who enters a residence (no-knock laws), but they definitely have prosecuted people for killing burglars in a business.
The question of recording a conversation depends on whether it is on the phone or in person. Different laws pertain to these, and different states have different laws regarding both of these situations.