In its amicus brief, the Department of Justice relies in part on flawed research findings as evidence that AR-15s are in “common use” and cannot be prohibited. For example, the Department cited a survey released days before briefs were due by a professor, William English, whose earlier work was criticized for — among other things — having “undisclosed ties to pro-gun interests.” English’s new research claims that roughly a quarter of gun owners own AR-15s. However, the new survey appears to suffer from many of the same flaws as his prior one; it was not peer-reviewed, does not disclose how respondents were recruited, and primes respondents to answer in certain ways.
The Department of Justice also cited figures from the National Shooting Sports Foundation (NSSF), the gun industry’s trade association, estimating that millions of “modern sporting rifles” — a term that the NSSF created for assault weapons like AR-15s — have been produced since 1990. But as discussed here, there is a stark difference between how many assault weapons have been made and how many are currently owned by civilians. The NSSF’s production figures do not distinguish between military, police, or civilian firearms and appear to include those in the hands of prohibited owners, such as criminals and domestic abusers, and those that have been illegally trafficked.
What cannot be argued is that assault weapons have become the weapon of choice for the perpetrators of the country’s most horrific mass shootings. Over 100 million Americans currently live in states that prohibit assault weapons, but those laws are now under attack, and the Trump administration chose to side with the gun lobby’s arguments and perspectives instead of protecting public safety.
— Greg Lickenbrock in Trump Admin Urges SCOTUS to Strike Down Assault Weapons Bans