A ban on “ghost guns” took effect in Oregon on Sunday, after a federal judge denied a challenge from gun rights groups seeking to block the restriction. The new law requires unfinished frames or receivers, and all firearms built after October 22, 1968 — the day President Lyndon B. Johnson signed the Gun Control Act into law — to have a serial number. It builds on regulations enacted in July 2023 that prohibit the possession of “undetectable firearms” and the sale of such unserialized guns and parts.

The new law comes shortly after Polymer80, once the country’s largest manufacturer of kits for making the homemade, untraceable guns, ceased operations. Its enactment illustrates one of the reasons for the closure: Because buyers could purchase Polymer80s without undergoing a background check, ghost guns quickly became a weapon of choice for criminals, putting the company in the crosshairs of policymakers and law enforcement across the country. The increased scrutiny resulted in a barrage of lawsuits and restrictions, similar to Oregon’s, that hurt the company’s bottom line. In settlements, Polymer80 agreed to stop selling ghost gun kits in California, Maryland, and parts of Pennsylvania.

Restrictions like Oregon’s, however, are under threat at the Supreme Court. In its new term, which starts in about a month, justices will consider a case challenging the Biden administration’s efforts to curb the sale of ghost guns. The case seeks to topple an ATF rule that requires sellers of “ready to build” kits to add serial numbers to some parts and conduct background checks on prospective buyers. A ruling against the federal government, The Trace’s Alain Stephens reported earlier this year, could jeopardize not only state bans on ghost guns but also numerous laws governing the manufacture and sale of firearms, broadening Second Amendment protections.

“As a matter of policy, I think it’s an unassailable, correct policy,” John Donohue, a Stanford law professor and gun policy expert, said about the rule. “The only question is whether it has been done in a way that allows the Supreme Court to throw a monkey wrench in the process.”

From The Trace

What to Know Today

Delano, California, a rural area near Los Angeles, has some of the highest rates of gun violence in the state. Dozens of families have lost loved ones — but most of the killings go unsolved. [The Guardian

More than 52,000 guns recovered in Mexico between 2015 and 2022 were traced to a U.S. purchase. New ATF data shows that more than 40 percent came from Texas. [Texas Observer

Applications for sentencing relief under the Oklahoma Survivors’ Act opened on Thursday, allowing domestic violence victims who have been convicted of a crime to seek a modified sentence if they can show that their abuse was related to the act. Among those asking for relief is April Rose Wilkens, who was sentenced to life in prison for shooting and killing her abuser in 1998. [Oklahoma Voice

FBI officials revealed new details on the attempted assassination of former President Donald Trump in July, announcing last week that an analysis of the shooter’s electronics suggested that he had been interested in committing acts of public violence for several years. Investigators still have not determined a motive. [USA TODAY/The New York Times

Meredith Elizalde, whose son Nicolas was shot and killed while leaving a football scrimmage at a Philadelphia high school in 2022, has filed a federal civil rights lawsuit against the School District of Philadelphia, accusing district officials of “ignoring the threat of gun violence” and organizing after-school activities “without adequate security and coordination with law enforcement.” Elizalde also filed a local suit against Pennsylvania’s high school athletic association with similar allegations. [The Philadelphia Inquirer

At least 17 Texas National Guard members have died while deployed on “Operation Lone Star,” the state’s three-year-old mission at the southern border, including one soldier who was accidentally shot and five who died by suicide. [Stars and Stripes

Police in Olympia, Washington, have been barred from personalizing city equipment under a settlement with the family of Timothy Green. Green, who was Black, was shot and killed in 2022 by an officer wearing a “Blue Lives Matter” emblem, and the commander on the scene had decorated his department-issued laptop with insignia that, per extremism researchers, represent right-wing, anti-government ideology. It wasn’t the first time Olympia police have been linked to far-right groups. [The Washington Post

How should we interpret the decline in homicides over the past couple of years? In an essay unpacking the trend, researcher John Roman argues that the most important data to examine is how gun use has changed over time. [External Processing]

Data Point

9.1 per 100,000 — the gun homicide rate in rural Kern County, California, which encompasses Delano, between 2016 and 2021. That was the highest rate per capita in the state, and much greater than the statewide average of 3.8. [The Guardian]

Non Sequitur

On off-topic story for a change of pace.

The Latina Quinceañera Tradition Is More Alive Than Ever — But It’s Not Your Abuela’s Celebration: Blowout parties with a “crazy hour,” reggaeton instead of the court waltz and epic photo shoots are just part of an evolving Latina teen rite of passage. [NBC]