As the US continues to be rocked by a chain of deadly mass shootings, lawmakers and the public have made loud calls to rein in firearm ownership through stronger federal gun laws.
This summer, President Joe Biden signed into law the Bipartisan Safer Communities Act — the most significant piece of gun legislation to pass in decades. Part of the bill includes $750 million in federal funding for states to implement intervention programs such as gun restraining orders, more colloquially known as "red flag laws."
The scope of the law varies by state, but it generally allows law enforcement, family members, and sometimes school staff to petition someone's firearms to be confiscated if they present a danger to themselves or to others.
But the Fourth of July shooting in Highland Park, Illinois, which killed seven people and injured dozens more put that measure under the spotlight once again.
The shooting suspect exhibited the types of issues that could have triggered Illinois' red flag law that was enacted in 2019, according to The Chicago Tribune. Yet, around 2020 and 2021, he was able to purchase the rifle used during the attack in a state with some of the strongest gun laws in the country, based on rankings from the Giffords Law Center to Prevent Gun Violence.
Insider also found at least eight other cases of shootings with three or more fatalities, in which the suspect or perpetrator was known to have shown concerning behaviors, such as threats to themselves or the public, by mental health evaluators, law enforcement, or family members, and purchased a firearm in a state with a gun restraining order.
Does this mean red flag laws don't work?
"Red flag laws are an intuitive law and they're a popular law," Veronica Pear, a researcher in the Violence Prevention Research Program at the University of California, Davis, who studied red flag laws in California, told Insider. "And, anecdotally, we can say that they've disarmed many people who were making threats of mass shootings."
When the law is used, Pear and her researchers found that the measure can be effective. Looking at California, researchers found that out of the 201 cases the state's gun restraining orders were utilized, almost 30% of them, or 58 cases, involved individuals making mass shooting threats.
Currently, 19 states and the District of Columbia have some form of a red flag law in place. About 16 of those jurisdictions enacted the law on or after 2018, following the Marjory Stoneman Douglas High School shooting in Parkland, Florida.
When California implemented its Gun Violence Restraining Orders in 2016, Pear's study found that law enforcement didn't take full advantage of the measure until at least two years after it went into effect.
"That would explain of course why we had so few orders issued in the first couple of years," she said.
Other issues Pear's research team found around implementation included a lack of funding for training and, in some cases, law enforcement's unwillingness to use the law, especially in areas where there is a strong culture of gun ownership.
"There can be cultural barriers within police departments," Pear said. "In Colorado, we saw sheriffs coming out and saying that they would refuse to petition for these orders."
Here are several cases where shooters slipped through the cracks of their state's red flag laws.