...
However, NAF's most current data, which only covers attacks by extremists who are either United States citizens or permanent residents, has been challenged over its categorizing of post-9/11 deadly attacks.
"For instance, NAF includes Joshua Cartwright on the list [of non-jihadists]. In 2009, Cartwright was reported to police after beating his wife. Police attempted to arrest him for domestic violence at a local shooting range. A shootout ensued in which two police officers were killed," conservative blogger John Sexton reported in April 2014.
"NAF apparently includes Cartwright on its list of terrorists because his wife remarked that he was 'severely disturbed' by the election of Barack Obama," he added.
The NAF database also excludes from its list of jihadist attacks the infamous Beltway Sniper, John Allen Muhammad, who was responsible for shooting and killing 10 Americans in 2002.
PunditFact, a division of the Tampa Bay Times, wrote in Jan. 2015, "Leave [the Beltway Sniper] deaths out of the equation for slayings on American soil, and the edge … still goes to the right-wing extremists."
However, PunditFact added, "If this exercise shows nothing else, it is that the number of post-9/11 deaths in the United States from either cause is low, and drawing firm conclusions is dicey. A single event or a change in definitions can shift the balance."
The fact-checking site added that defining the nature of deadly attacks makes all the difference, explaining that many of the killers acted on their own.