(CNN)After 19-year-old Brandon Hole killed eight people at a FedEx facility in Indianapolis last week, questions arose about the state's "red flag" law, which should have prevented Hole from having a gun in the first place.
Indiana's 'red flag' law should have prevented the FedEx shooting. Here's what else you should know about these laws
"Red flag" laws, found in more than a dozen states across the US, are also known as Extreme Risk Protection Order laws -- and they allow courts to temporarily seize firearms from anyone believed to be a danger to themselves or others.
In Hole's case, his mother told law enforcement in March 2020 that her son told her he would attempt "suicide by cop." At the time, officials took a shotgun found at his home into custody, Marion County prosecutor Ryan Mears said Monday. And yet, later that year, Hole was able to legally purchase assault rifles.
The situation shows the limits of Indiana's "red flag" law, Mears said. In Indiana, after the state has seized the firearm, it has 14 days to file a petition requesting the person be designated as having a violent propensity or mental instability. But because the gun from Hole's home had been secured and the family didn't want it back, the prosecutors at the time felt they "achieved" the objective of the law, Mears said. If the state had filed a petition, the court might have determined prosecutors didn't have the legal authority to keep the weapon, Mears said.
Thus, no petition was filed. And four months later, Hole was able to purchase an assault rifle that he later used in the FedEx attack.
Red flag laws, when employed, can often keep firearms out of hands that may abuse them. But the laws, as the mass killing in Indiana shows, aren't always used to their fullest extent.
Michael Lawlor, a professor at the University of New Haven, helped write Connecticut's red flag law -- the first in the US -- as a member of the state legislature in 1999. He told CNN that red flag laws are one tool, but they don't work without a comprehensive system of gun regulation. He used the incident in Indiana as an example.
"In Indiana, they have the red flag law ... but they don't have the mechanism to make it difficult to get out and get more guns," Lawlor said.
In contrast, Connecticut has rules against people under 21 buying firearms and does not allow the purchase of assault rifles, he said. Both rules would have stopped Hole.
Furthermore, Lawlor pointed out that if officers had enough evidence to seize the handgun in the first place, they probably had enough to file a petition, which would have prohibited Hole from buying the assault rifles later on. In Connecticut, Lawlor said it would have been a "no-brainer," and he said he assumed that in Indiana officials may not have been familiar with how the law was supposed to work.
This presents another limit of red flag laws -- sometimes, officers and local authorities simply don't always know how to use it.
In Connecticut, Lawlor said it took six or seven years after the law was enacted for police to become familiar with how to use the power. Then, prosecutors and judges had to learn, too.
A similar situation to Indiana happened in November 2018, when Ian David Long killed 12 people and injured over a dozen more during a mass shooting at a bar in Thousand Oaks, California. A few months earlier, in April, officers responded to a disturbance at Long's home, after he was acting irate, according to the county sheriff. A mental health specialist met with Long, concluding that he may have PTSD from his time in Afghanistan serving with the US Marines.
California has a red flag law, which could have been employed in this situation but wasn't.
Still, the comprehensive system of gun regulation is key, Lawlor said.
"Great, you take the gun away, but what do you do after that?" he asked. "How do you ensure this person isn't going to act out in a week or two?"
Initially, after the first red flag law was enacted in Connecticut 22 years ago, a few states followed suit. Indiana did so in 2005, and in 2016 Washington and California followed, according to data collected by Everytown, an organization working to end gun violence.
Since the 2018 shooting at Stoneman Douglas High School in Parkland, Florida, there are 19 states and Washington D.C. that have enacted some type of red flag law, according to Everytown: California, Colorado, Connecticut, Delaware, Florida, Hawaii, Illinois, Indiana, Maryland, Massachusetts, Nevada, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia, and Washington.
This month, President Joe Biden announced he would enact several gun-control executive orders, following a series of mass shootings. One of those involved creating model "red flag" legislation for states to pass.
Red flag laws tend to be supported by those favoring gun control, arguing that the policies can prohibit mass shootings from happening in the first place.
"These laws can help de-escalate emergency situations and are a proven way to intervene before gun violence such as a firearm suicide or mass shooting takes more American lives," Everytown wrote this year.
In 54% of cases, the shooter exhibited warning signs that they posed a risk to themselves or others, Everytown said after it analyzed mass shootings between 2009 and 2018.
But gun rights activists feel differently.
The National Rifle Association, for example, typically does not support red flag laws, as it argues the laws do not protect a person's due process rights.
But Lawlor argued that in most cases red flag laws operate in the same way as search or arrest warrants operate: Officers bring the evidence to the judge, who makes a decision and allows law enforcement to act prior to having a hearing.
And still, in some instances, gun advocates, including members of law enforcement, have come out against the law, arguing it infringes on the person's Second Amendment rights.
After New Mexico enacted its red flag law last year, the head of the New Mexico Sheriffs' Association, Tony Mace, wrote a public letter disavowing the policy for that very reason.
"Citizens have a right to bear arms and we cannot circumvent that right when they have not even committed a crime or even been accused of committing one," he wrote. "'Shall not be infringed' is a very clear and concise component of an Amendment that our forefathers felt was important enough to be recognized immediately following freedom of speech and religion."