HIGHLAND PARK, Ill. — The father of a man charged with fatally shooting seven people at a Fourth of July parade in suburban Chicago appeared in court Friday.

Robert Crimo Jr. entered a not guilty plea in February to charges that he helped his son obtain a gun license three years before the attack.

He was arrested and charged in December 2022 on seven felony counts of reckless conduct — one count for each person killed. Each count carries a maximum 3-year prison term.

Lake County State’s Attorney Eric Rinehart has said the accusations against Crimo Jr. are based on his sponsorship of his son’s application for a gun license in December 2019.

“Parents and guardians are in the best position to decide whether their teenagers should have a weapon,” Rinehart said after the father’s arrest. “In this case, the system failed when Robert Crimo Jr. sponsored his son. He knew what he knew and he signed the form anyway.”

Legal experts have said it’s rare for an accused shooter’s parent or guardian to face charges — in part because it’s difficult to prove such charges.

The father is a familiar face around Highland Park, where he was once a mayoral candidate and operated convenience stores.

In 2022, a grand jury indicted his son, Robert Crimo III, on 21 first-degree murder counts, 48 counts of attempted murder and 48 counts of aggravated battery, representing the seven people killed and dozens wounded in the attack at the holiday parade in Highland Park.

Authorities say Illinois State Police reviewed Crimo III’s gun license application and found no reason to deny it because he had no arrests, no criminal record, no serious mental health problems, no orders of protection and no other behavior that would disqualify him.

A federal warrant unsealed in March said federal agents found bomb-making materials at the apartment of Crimo III. Among the items found in the Highland Park home days after the attack were commercial components used for explosions and a timer, according to the Chicago Tribune report.

An affidavit attached to the warrant cited Crimo as telling FBI agents he mulled the possibility of deploying explosives in the attack on the annual holiday parade in Highland Park, just north of Chicago.

The affidavit said that Crimo also told agents the explosives would have been “too heavy to carry to the parade, but he considered using them if the opportunity arose.”

The warrant was filed in U.S. District Court shortly after the shooting, though no federal charges have been filed in the case, the Tribune reported.

The Associated Press contributed to this article.