One focus is on the state’s so-called red-flag law, which enables parents, roommates and police to ask courts to seize guns from people who show signs they could turn violent. Nineteen states and the District of Columbia have such laws.

Here’s a look at Illinois’ red-flag and gun-licensing laws, and whether they could have been applied to Crimo:

WHAT IS ILLINOIS’ RED-FLAG LAW?

The law, which took effect on Jan. 1, 2019, authorizes judges to order the temporary removal of firearms from people deemed dangerous to themselves or others, according to the Illinois Criminal Justice Information Authority, a state agency.

The order, called a firearm restraining order, also bars them from buying guns. It is separate from domestic violence restraining orders and laws that mandate reporting of certain behavior by some professionals, such as teachers.

Illinois’ red-flag law, as in many states, is a civil matter. It is meant to be invoked within hours or days of someone making threats or displaying threatening behavior. The order is not meant to be invoked as a result of a clear crime.

DID CRIMO EVER DISPLAY THE KIND OF BEHAVIOR MEANT TO ACTIVATE THE LAW?

It appears that he did. But it isn’t clear just who knew about it and when, and whether law enforcement agencies took the behavior seriously enough.

Less than three years ago, police went to Crimo’s home following a call from a family member who said he was threatening “to kill everyone” there, according to Christopher Covelli, a spokesman for the Lake County Major Crime Task Force.

Police confiscated 16 knives, a dagger and a sword, but said there was no sign he had any guns at the time, in September 2019. Earlier, in April 2019, police also responded to a reported suicide attempt by Crimo, Covelli said.

DOES THAT MEAN CRIMO BOUGHT THE GUN LEGALLY?

Yes. He legally purchased the Smith and Wesson M&P 15 semi-automatic rifle in Illinois within the past year.

Illinois State Police, the agency that issues gun owners’ licenses, said in a statement that the then-19-year-old Crimo applied for a license in December 2019. Applicants under 21 require a parent or legal guardian to sponsor the application. His father sponsored his.

Sponsors must sign an affidavit that says the sponsor “shall be liable for any damages resulting from the minor applicant’s use of firearms or firearm ammunition.” It includes no specifics on liability and damages if the child commits a crime with a gun. It’s also unclear if liability extends beyond when the child turns 21, as Crimo did before the shooting.

State Police Director Brendan Kelly told reporters Wednesday that the father faces potential civil liability, and that there is an ongoing investigation into criminal culpability. He offer no details and said the matter would ultimately be decided in court.

A Crimo family attorney, Steve Greenberg, told the Chicago Tribune that the father was not aware of the threats when he helped his son with the application because his son lived with another relative at the time.

Asked if the suspect’s parents might face any charges as a consequence of what their son did, Greenberg told The Associated Press on Tuesday that “there is zero chance they will be charged with anything criminal.” He added: “They didn’t do anything wrong.”

DID HIGHLAND PARK POLICE PASS INFORMATION ABOUT THE THREATS TO STATE POLICE?

They did, though they did not take one step available to them under the red flag law: Ask for a firearm restraining order.

State police have confirmed they got a warning from Highland Park police months before Crimo applied for his gun license. It’s not clear if the state agency went through Highland Park’s report before granting the license.

A statement from state police said only that “there was insufficient basis to establish a clear and present danger” to deny the application.

Under Illinois law, if Crimo had a felony conviction or had been committed for major mental health problems, he likely would not have gotten the license. He had no such record.

IS THE LAW INVOKED OFTEN?

No, though related records are sometimes sealed, so it’s difficult to get a full picture. Illinois legislation in 2021 included provisions to increase awareness among law enforcement and the general public about how to use red-flag laws.

The Illinois Criminal Justice Information Authority cites tracking done by one advocacy group, Speak for Safety Illinois. The organization reported it found that 34 firearm restraining orders were filed in 2019 and 19 in 2020. Most were granted.

One suburban Chicago county, DuPage County, accounted for 12 of the filings in each year, it said. And no other county, including Lake County, which includes Highland Park, filed more than two in those years.

The vast majority of filings were by law enforcement, with family members accounting for just five filings in 2019.

WHO CAN REQUEST AN ORDER AND HOW IS A DECISION MADE?

A relative, roommate or law enforcement officer can make the request by submitting an application with a local circuit court. In some cases, others not explicitly authorized by law to apply can seek to initiate the process by contacting police.

Red-flag laws in some states permit doctors, teachers and colleagues to file requests. Elsewhere, laws limit filings solely to law enforcement.

In Illinois, the burden of proving someone is a threat falls on those who file the request. Among other evidence, they can offer witness statements about violent behavior and police records, or any threatening social media posts and emails.

If a judge sides with the petitioner, the court issues a firearm restraining order, which allows law enforcement to immediately seize any guns from the person deemed a threat and bars them from purchasing guns and ammunition.

They must also turn in their firearm owner’s identification card.

WHAT HAPPENS AFTER AN ORDER IS ISSUED?

An emergency order can been issued the same day and remains in effect for up to 14 days. The judge can rule on it without the presence of the subject of the request.

If the emergency order is issued, it is followed by a full hearing after which a judge will decide if a longer, six-month order is warranted. The standard of proof is higher at such a hearing. And subjects can argue before the judge why an order isn’t called for.

If the six-month order is issued, it cannot be easily extended. If the person who filed the initial request believes the subject still poses a danger, another hearing with the same higher level of proof must be held again.

DO RED-FLAG LAWS PREVENT VIOLENCE?

According to the Illinois Criminal Justice Information Authority, there’s clear evidence that firearm restraining orders help prevent some suicides. It’s less clear that they prevent deadly acts of gun violence, like mass shootings. The agency says the causes of such attacks are often too multifaceted to draw clear links.