HIGHLAND PARK, Ill (AP) — The man charged with killing seven people when he unleashed a hail of bullets on an Independence Day parade from a rooftop was expected in court Wednesday as authorities faced questions about how he was allowed to buy several guns, despite threatening violence.

Robert E. Crimo III was charged with seven counts of murder Tuesday in the shooting that sent hundreds of marchers, parents and children fleeing in fear and set off an hourslong manhunt in and around Highland Park, an affluent Chicago suburb on the shores of Lake Michigan. Investigators have yet to identify a motive.

Crimo’s attorney said he intends to enter a not guilty plea to all charges. Prosecutors have promised to seek dozens more.

A rifle “similar to an AR-15” was used to spray more than 70 rounds from atop a commercial building into the parade crowd, a spokesman for the Lake County Major Crime Task Force said.

A seventh victim died Tuesday. More than three dozen other people were wounded in the attack, which Task force spokesman Christopher Covelli said the suspect had planned for several weeks.

The assault happened less than three years after police went to Crimo’s home following a call from a family member who said he was threatening “to kill everyone” there. Covelli said 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.

Police in April 2019 also responded to a reported suicide attempt by the suspect, Covelli said.

Crimo legally purchased the rifle used in the attack in Illinois within the past year, Covelli said. In all, police said, he purchased five firearms, which were recovered by officers at his father’s home.

The revelation about his gun purchases is just the latest example of young men who were able to obtain guns and carry out massacres in recent months despite glaring warning signs about their mental health and inclination to violence.

Illinois state police, who issue gun owners’ licences, said Crimo applied for a licence in December 2019, when he was 19. His father sponsored his application.

At the time “there was insufficient basis to establish a clear and present danger” and denied the application, state police said in a statement.

Investigators who have interrogated the suspect and reviewed his social media posts have not determined a motive or found any indication that he targeted victims by race, religion or other protected status, Covelli said.

At the July 4 parade, the shots were initially mistaken for fireworks before hundreds of revelers fled in terror. A day later, baby strollers, lawn chairs and other items left behind by panicked parade goers remained inside a wide police perimeter. Outside the police tape, some residents drove up to collect blankets and chairs they abandoned.

David Shapiro, 47, said the gunfire quickly turned the parade into “chaos.”

“People didn’t know right away where the gunfire was coming from, whether the gunman was in front or behind you chasing you,” he said Tuesday as he retrieved a stroller and lawn chairs.

The shooting occurred at a spot on the parade route where many residents had staked out prime viewing points early in the day.

Among them was Nicolas Toledo, who was visiting his family in Illinois from Mexico, and Jacki Sundheim, a lifelong congregant and staff member at nearby North Shore Congregation Israel.

Nine people, ranging from 14 to 70, remained hospitalised Tuesday, hospital officials said.

The shooting was just the latest to shatter the rituals of American life. Schools, churches, grocery stores and now community parades have all become killing grounds in recent months. This time, the bloodshed came as the nation tried to celebrate its founding and the bonds that still hold it together.

The gunman initially evaded capture by dressing as a woman and blending into the fleeing crowd, Covelli said.

A police officer pulled over 21-year-old Crimo north of the shooting scene several hours after police released his photo and warned that he was likely armed and dangerous, Highland Park Police Chief Lou Jogmen said.

Asked about his client’s emotional state, prominent Chicago-based lawyer Thomas A. Durkin said he has spoken to Crimo only once — for 10 minutes by phone. He declined to comment further.

In 2013, Highland Park officials approved a ban on semi-automatic weapons and large-capacity ammunition magazines. A local doctor and the Illinois State Rifle Association quickly challenged the liberal suburb’s stance. The legal fight ended at the U.S. Supreme Court’s doorstep in 2015 when justices declined to hear the case and let the suburb’s restrictions remain in place.

Under Illinois law, gun purchases can be denied to people convicted of felonies, addicted to narcotics or those deemed capable of harming themselves or others. That last provision might have stopped a suicidal Crimo from getting a weapon.

But under the law, who that provision applies to must be decided by “a court, board, commission or other legal authority.”

The state has a so-called red flag law designed to stop dangerous people before they kill, but it requires family members, relatives, roommates or police to ask a judge to order guns seized.

Crimo, who goes by the name Bobby, was an aspiring rapper with the stage name Awake the Rapper, posting on social media dozens of videos and songs, some ominous and violent.

Federal agents were reviewing Crimo’s online profiles, and a preliminary examination of his internet history indicated that he had researched mass killings and had downloaded multiple photos depicting violent acts, including a beheading, a law enforcement official said.

The official could not discuss details of the investigation publicly and spoke to The Associated Press on condition of anonymity.

Shapiro, the Highland Park resident who fled the parade with his family, said his 4-year-old son woke up screaming later that night.

“He is too young to understand what happened,” Shapiro said. “But he knows something bad happened.”