(NewsNation) — The suspect in Monday’s mass shooting at a Fourth of July parade fired more than 70 rounds at innocent bystanders and had allegedly planned the attack for several weeks, officials said Tuesday.

Authorities have charged 21-year-old Robert “Bobby” Crimo III with seven counts of murder in connection to the attack at an Independence Day celebration in Highland Park, Illinois that left seven people dead and more than 30 wounded. Additional charges are expected to be announced in the coming days.

Law enforcement took Crimo into custody “without incident” Monday evening, after an hourslong manhunt following the shooting.

Crimo was known to authorities after two separate incidents in 2019, officials said at a press conference Tuesday afternoon.

In April 2019, an individual contacted Highland Park Police Department after learning Robert Crimo had attempted suicide. That matter was handled by mental health professionals, according to Lake County Major Crime Task Force spokesman Christopher Covelli.

If you or someone you know is thinking of harming themselves, the National Suicide Prevention Lifeline provides free support at 1-800-273-8255. Starting on July 16, 2022, U.S. residents can also be connected to the Lifeline by dialing 988. For more about risk factors and warning signs, visit the organization’s official website.

Five months later a family member called police and said Crimo had threatened to “kill everyone” in the household. Authorities responded to the residence and removed 16 knives, a dagger and a sword, Covelli said.

“At that time there was no probable cause to arrest, there were no complaints that were signed by any of the victims,” Covelli said, adding that the Highland Park Police Department did notify state police of the incident.

Steve Greenberg, the attorney for Crimo’s parents, told NewsNation Tuesday that his clients dispute what police have said about their son being suicidal and threatening to kill them.

State police said they received a “clear and present danger” report after the knife incident in 2019 but Crimo’s father claimed the knives were his and declined to move forward with a complaint.

Just months after the alleged knife incident, Crimo’s father sponsored his son’s gun license in December 2019, state police said. Robert Crimo was 19 years old at the time.

Crimo later passed four different firearms background checks between June 2020 and September 2021, according to state police.

Officials said Crimo legally purchased the “high-powered rifle” used in Monday’s massacre in the Chicagoland region.

Authorities found an additional rifle in Crimo’s possession when he was arrested. Law enforcement later discovered more firearms at the 21-year-old’s residence. All five of the weapons were legally purchased in Crimo’s name after the 2019 incident, Covelli said.

Although it’s unclear what type of rifle Crimo allegedly used in Monday’s attack, Covelli described it as “similar to an AR-15.”

The 21-year-old suspect was an aspiring rapper who went by “Awake the Rapper” online. He had posted dozens of videos and songs on social media, many of which contained ominous, violent imagery.

In one animated video that’s since been taken down by YouTube, Crimo raps about armies “walking in darkness” as a drawing appears of a man pointing a rifle, a body on the ground and another figure with hands up in the distance.

In another video, in which Crimo appears in a classroom wearing a black bicycle helmet. He says: “Everything has led up to this. Nothing can stop me, even myself.”

Another clip, which was posted in March, shows a newspaper headline of presidential assassin Lee Harvey Oswald tacked to a wall behind Crimo.

Covelli said Monday that authorities were not aware of the disturbing videos online.

An initial background check by WGN did not reveal a criminal record and found that Crimo had not been in custody in Lake County or Cook County in the last few years.

As of Tuesday, investigators had not determined a motive and said the attack appears to be random.

“We have no information to suggest at this point it was racially motivated, motivated by religion or any other protected status,” Covelli said.

The suspect, who is from Highland Park, had been living in separate apartments in a duplex with his father Bob Crimo and uncle, Paul Crimo, the suspect’s uncle said on “Morning in America.” Paul Crimo said he didn’t know anything about his nephew’s weapon and didn’t watch the disturbing content Robert Crimo had posted online.

Paul Crimo told FOX-32 Chicago he had last seen Robert Crimo the evening before the shooting and that there were no warning signs that something was wrong. It’s unclear whether Crimo’s uncle was present or aware of the prior 2019 incidents.

The alleged shooter’s uncle said the 21-year-old, who lived in a separate apartment on the family’s property, was unemployed and had not gone to college, describing him as a “YouTube rapper.”

Paul Crimo, who appeared visibly distraught, offered his condolences to all the victims in Monday’s shooting and said he’s heartbroken by it: “I’m very sorry from the bottom of my heart and I’m just so sorry that this happened.”

“The last two years, I saw no signs of trouble. He showed no aggressions toward me and no violent outbreak,” Paul Crimo said on “Morning in America.”

NewsNation spoke with a former classmate of Robert Crimo’s who thought the alleged shooter had behavioral issues but was surprised that he turned violent.

“There were red flags but I didn’t think again that they were violent red flags. I thought he was troubled,” said Ethan Absler.

Highland Park Mayor Nancy Rotering told NBC’s “Today” she knew Crimo as a young boy when she was his Cub Scout pack leader.

“What happened? How did somebody become this angry, this hateful to then take it out on innocent people who literally were just having a family day out?” Rotering said.

The suspect’s father, Bob Crimo, a longtime deli owner, had previously run for mayor of Highland Park in 2019.

The Associated Press contributed to this report.