In a 94-page decision, federal Judge Roger T Benitez described California's assault weapons ban - in place in 1989 - as unconstitutional and defended the right of Americans to own semi-automatic rifles.
The comparison of the AR-15 to a versatile pocket knife favored by campers drew sharp criticism from California officials including Gov. Gavin Newsom, who called the AR-15 a "weapon of war".
"My daughter is in a cemetery because a Swiss Army Knife was not used, because it was an AR-15", he said.
He said the Swiss Army knife comparison undermined the "credibility" of the ruling and was a "slap in the face to the families who've lost loved ones to this weapon".
Barring them has proven the state's preservation of public safety. "We won't stand for it".
Judge Roger T Benitez, who has favoured gun rights organisations in previous rulings, described the rifle - which has been the go-to gun for numerous nation's deadliest mass shooters - as the pinnacle of home self-defense. These and other points make the Swiss Army knife comparison far more reasonable than it appears at first blush.
"Like the Swiss Army Knife, the popular AR-15 rifle is a flawless combination of home defense weapon and homeland defense equipment", Benitez said in the ruling. "Good for both home and battle".
The lawsuit said California is one of only a small handful states to ban numerous most popular semiautomatic firearms in the nation because they possess one or more common characteristics, such as pistol grips and threaded barrels, frequently but not exclusively along with detachable ammunition magazines.
In 2019, California resident James Miller and several state gun rights groups including the San Diego County Gun Owners Political Action Committee, California Gun Rights Foundation, Second Amendment Foundation, and Firearms Policy Coalition challenged the law in court.
The judge noted that the legacy media twists the facts on gun ownership. "The facts, however, do not support this hyperbole, and facts matter". The second type is a semiautomatic centerfire rifle that has a fixed magazine that can hold 10 or more rounds. "There is no sound basis in law, fact, or common sense for equating assault rifles with swiss army knives", Bonta added.
They say California's ban on anyone under the age of 21 owning guns is age-discrminiation, and infringes on the rights of law-abiding young adults.
Still, an AR-15 style rifle has been the weapon of choice for the most violent mass killings in modern history, including in a movie theater in Aurora, Colorado; the Tree of Life synagogue in Pittsburgh; the Route 91 Harvest musical festival in Las Vegas; a massacre at a church in Texas; the Pulse nightclub in Orlando; a high school in Parkland, Florida; and the Sandy Hook Elementary School in CT.
The judge noted that California appears to define "assault weapon" in terms of accuracy under fire.
California has ended its ban on assault rifles after 32 years. The first type is a semiautomatic centerfire rifle that does not have a fixed magazine but has one of the following prohibiting features: a pistol grip that protrudes conspicuously beneath the action of the rifle, a thumbhole stock, a folding or telescoping stock, a grenade or flare launcher, a flash suppressor, or a forward pistol grip.
Further, a surge in sales of more than 1.16 million other types of pistols, rifles and shotguns in the past year - more than a third of them to likely first-time buyers - show that the assault weapons ban "has not prevented law-abiding citizens in the state from acquiring a range of firearms for lawful purposes, including self-defense", the state contended in a court filing in March. After all, responsible gun-owners worry about the ending point of every round fired.
California´s attorney general Rob Bonta argued that assault weapons as defined by the law are more risky than other firearms and are disproportionately used in crimes and mass shootings. In the last hour, he shared a tweet listing mass shootings and the weapon used. On the other hand, in the self-defense context, which seems to be more common, taking accurate shots at attackers is vitally important for the innocent victim.