Stephan Blandin joins Megan Hickey to discuss potential liability of Highland Park Gunman's father

As Highland Park residents continue to move forward, many are asking if the suspect's parents could be liable for the deadly mass shooting on Monday.

CBS 2 Investigator Megan Hickey has been digging into that question. According to legal experts, charges could be on the table.

So far prosecutors have been very hesitant to say anything on the record about charges against the suspected shooter's parents.

But one legal expert said there could be a case to charge the dad, and that's only four days into the investigation.

On Thursday, the attorney for the suspected shooter's parents – Robert Crimo Jr and Denise Pesina – said they wouldn't be making any public comments going forward, but said "the parents will continue to speak with law-enforcement and to assist them."

Attorney Steve Greenberg had previously tweeted that the parents were not to blame for what happened, saying, "ISP should ask why did THEY approve a FOID card and why do THEY allow the sale of assault weapons?"

The suspect's father sponsored his FOID card application just three months after an incident in which police were called to the family's home, because the suspect was threatening to kill them with a collection of knives and swords.

The suspect's father, who is mentioned several times in that police report, would have had to sign a two-page waiver attesting to his ability to be a sponsor.

It doesn't ask anything about the person applying for the FOID card, but state statute reads: "the parent or legal guardian giving the consent shall be liable for any damages resulting from the applicant's use of firearms or firearm ammunition."

"If the state doesn't press charges, then they're admitting that the whole statute is a sham," said attorney Stephan Blandin, whose firm has represented many victims of mass shootings across the country.

Asked if the suspect's father could face any liability for the shooting, Illinois State Police Director Brendan Kelly said it would be inappropriate for him to draw any conclusions amid an ongoing criminal investigation of the shooting, as well as the potential for civil litigation.

Blandin said there seems to be a clear case against the father when it comes to the FOID sponsorship, but prosecutors might be afraid to answer definitively, because gun issues are so political.

As for the mother or any additional liability on the father?

"I'm quite positive that there are a number of individuals, who live in that neighborhood, who have information about what took place in the days and weeks and months leading up to this; and that that will come out and come forward," Blandin said.

The suspect's father did not respond to requests for comment from CBS 2; but in a phone interview with ABC News, he said doesn't know the motive behind his son's actions, and defended his decision to sponsor his son's FOID card application.

He said he and his wife asked their son if had any plans for the 4th of July and he simply replied, "no."