An Illinois father pleaded guilty on Monday to multiple counts of reckless conduct for helping his troubled underage son obtain a gun that the latter used to kill seven people at a Fourth of July parade in 2022.

Illinois Circuit Court Judge George Strickland sentenced Robert Crimo Jr. to two years of probation and 60 days in custody of the Lake County sheriff, as well as 100 hours of public service. The father of the accused shooter was also ordered to surrender his firearm owner identification card and any ammunition.

Crimo Jr.'s lawyer told reporters outside the courtroom that his client had pleaded guilty to prevent his trial from becoming a "public spectacle" or jeopardizing his son's case by disclosing key evidence before the younger Crimo's trial.

The case against Crimo Jr. marks at least the second time a parent in the United States has been prosecuted in connection with crimes allegedly committed by their child. Experts say the guilty plea could help expand the number of people held liable in future mass shootings.

In October, the Michigan Supreme Court ruled that the parents of a teenager who shot four classmates to death at a Detroit-area high school would stand trial for involuntary manslaughter for buying their son a firearm despite knowing he was mentally disturbed.

In the Highland Park, Illinois, case, police say Robert Crimo III fired on spectators watching an Independence Day parade on July 4, 2022, killing seven people and injuring dozens. He pleaded not guilty to 117 counts, including 21 charges of first-degree murder.

A grand jury charged the elder Crimo in February with seven counts of reckless conduct for sponsoring his son's 2019 application for a firearm owner identification (FOID) card, despite knowing his son was unfit to own a gun.

At the time, the younger Crimo was under 21 and could not have legally applied for a FOID card without a parent or guardian signing for him.

The younger Crimo used the FOID card to buy five guns between 2020 and 2021, including the firearm that police said he used to shoot his victims from a sniper's perch on a rooftop above the parade route in 2022. He was 21 at the time of the shooting.

Local police received reports in September 2019 that the younger Crimo had allegedly directed threats to "kill everyone" at his family members and searched his home.

They seized a collection of 16 knives, a dagger and a sword amassed by Crimo, though no arrest was made, as authorities at the time lacked probable cause to take him into custody, authorities said.

(Cover: The U.S. Flags on the National Mall and past the U.S. Capitol Building in Washington, D.C., U.S., November 7, 2022. /CFP)