No the US has more than it's fair share of murders and you know that. But the statistics can be misleading. There are approximately 17,000 deaths by firearm in the US each year.
The part that is rarely discussed is how these numbers are arrived at. Everything is included in that number, suicides, people that are shot while committing a robbery or attempted murder, legitimate shootings by police, they are all part of the numbers.
In the case of the thread starter if those 2 guys had kicked in the door and started shooting and the TS fired back killing them, it would be 2 more deaths by firearm in the statistics even though both of the attackers were justifiably shot.
In 2014 the number of actual murders in the US listed in the FBI Uniform Crime Stats was 8124. In a country of 330,000,000 people.
https://ucr.fbi.gov/crime-in-the-u....able_8_murder_victims_by_weapon_2010-2014.xls