21-year-old Robert Crimo III, found to be the assailant who went on a shooting spree during a July 4 parade in Highland Park, Illinois, has confessed to the attack that claimed the lives of seven people and injured dozens, authorities said. Crimo also confessed to mulling committing a similar shooting in Wisconsin on the same day.

Crimo was apprehended without bond due to the threat he poses to the community, an Illinois judge ruled during the assailant's first court appearance since the massacre took place.

He currently faces seven counts of first-degree murder on Tuesday, with lake Country State's Attorney Eric Rinehart stressing that there would be more charges. "We anticipate dozens of more charges centered around each of the victims."

The initial death toll stood at six victims. However, police spokesperson Christopher Covelli said the toll rose to seven on Tuesday after one of those injured succumbed to their wounds and died in the hospital.

If convicted on the murder charges raised against him, Crimo could face life in prison without parole. 

The assailant's parents said they saw no signs of their son intending to carry out such a crime and they have no idea what the motivation behind it was. The authorities were trying to determine whether the attack was racially motivated or motivated by any other protected status, such as religion.

Law enforcement officers had been called twice to the assailant's home in 2019, once to investigate a suicide attempt and a second because a relative said he had threatened to "kill everyone" in the family, a spokesperson for the police revealed.

Crimo's father signed a consent form in 2019 allowing his son, then under 21, to apply for a card that authorizes Illinois residents to own a firearm.

The July 4 shooting was the latest in an epidemic of gun violence that has long been ravaging the United States, with authorities still debating stricter gun laws despite the latest spree of massacres. Around 40,000 deaths a year are caused by firearms in the US, according to the Gun Violence Archive.

Two shootings in May that left 21 people dead, mostly young children, at an elementary school in Texas and 10 Black grocery patrons dead in upstate New York revived the US' bitter debate over gun regulation.

The recent spike in tragic shootings has pushed guns to the forefront of a national debate as US leaders grapple with how to reduce the alarming rate of violence.

The US Senate recently passed a bill aimed at curbing the gun violence ravaging the United States, which has been particularly rampant over the past couple of months.