Fox News contributor and former D.C. homicide detective Ted Williams on Wednesday called for an investigation into the parents of the suspect accused of killing at least seven and injuring dozens more at the Highland Park Fourth of July parade, telling Fox News that there is "something very troubling" about their past handling of the 21-year-old's violent tendencies leading up to the massacre.

In an appearance on "Your World," Williams noted the suspected shooter, Robert E. Crimo III, was involved in two "prior incidents" before the mass shooting, which included a suicide attempt and threatening behavior involving knives, authorities confirmed. Despite this, Crimo's father allegedly helped his son obtain several guns, sponsoring the minor's firearm owners identification card two and half years ago when he was just 19.

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"We have to look at the parents," Williams told host Neil Cavuto. "They knew he had suffered and tried to commit suicide. And to go and buy guns with your son who has already tried to commit suicide, to go and buy guns with your son who has threatened family members to the point where you had to take knives out of the house, something is very troubling there. And that’s going to have to be a part of this investigation also."

Robert Crimo III booking photo from AP

Suspected shooter Robert E. Crimo III  (AP/handout from Lake County Major Crime Task Force)

Illinois State Police said Tuesday that the younger Crimo passed firearms background checks four times in the past two years, including three checks between June and July 2020. One of his legally purchased firearms, according to authorities, was the Smith & Wesson M&P 15 rifle prosecutors allege he used to fire on parade spectators from a rooftop perch Monday. Crimo was not flagged by Illinois' "red flag" laws, which were implemented to prevent people with violent histories or tendencies from obtaining weapons.

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Williams faulted the Illinois State Police for failing to properly log Crimo's violent behavior in their database when they responded to a call in September 2019 where they were forced to remove all knives from Crimo's home after he made violent threats against family members. Williams said their negligence likely caused Crimo's violent history to slip "through the cracks" during his various background checks.

"The police, from…what I seen, have dropped the ball," Williams said. "Because it did not go into any of their data banks. So when this guy and his father decided to go and purchase these weapons, it did not show up in any of the background or any of the ‘red flags’ that it would normally show up in. So he was permitted to get those weapons. The thing about it is, one of those weapons was the assault weapon that was used to shoot into that crowd and kill all of those people."

Robert Crimo Jr and Robert Crimo III

Illinois State Police say Robert Crimo Jr. sponsored his son's application for a Firearm Owner Identification card in 2019, three years before Robert Crimo III was accused of opening fire on a Fourth of July parade in Highland Park. (Facebook, Highland Park Police)

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"Let me say that Illinois has some of the most stringent gun laws in this country," he added. "They have red flag laws. They have universal background checks…so all of these things were in place in some kind of way. Some way [somehow], this slipped through the cracks. And as a result of that, this individual got on that building, shot down in that crowd and took seven beautiful souls out. [injuring] 30 or more individuals. 

"It’s very troubling," Williams said, adding that he hopes the investigation will further examine "how he was able to get past some of the red flag laws there in Illinois."