Australian police have charged 43-year-old Brendan Nugent over the alleged attack on independent lawmaker Helen Haines, according to an official with knowledge of the situation who was not authorized to speak publicly.

Nugent was due to appear in Wangaratta Magistrates’ Court on Wednesday, according to the court’s website. He was charged with causing harm to a Commonwealth public official, intentionally causing serious harm and dangerous driving, according to a statement from police on Tuesday.

Haines was hit by a car outside her office in a rural town in the state of Victoria on Monday. The investigation is being supported by the joint counterterrorism task force, including the Australian spy agency ASIO.

“We do believe this was a deliberate but isolated incident,” said Victoria Police Chief Commissioner Mike Bush at a press conference on Wednesday, adding that the state authorities had “no intelligence holdings” against Nugent. “There was nothing known to us that would’ve arisen or piqued our interest or given any indication that he was an immediate threat,” Bush said.

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It was unclear if Nugent has legal representation. In a statement obtained by the Guardian, Nugent’s father and his wife said that Haines had been a friend for decades and called the attack “unfathomable.”

According to the court website, a hearing was scheduled Wednesday for Nugent in the Wangaratta court, however no charges were mentioned. Federal and state authorities say that they are still trying to determine the motives for the attack.

Haines was injured on Monday afternoon as she retrieved something from the boot of her car, when another vehicle made a U-turn and struck her, Prime Minister Anthony Albanese said on television Tuesday morning.

Haines, 65, was rushed to a local hospital and then to Melbourne, where she underwent emergency surgery on Monday night. The national broadcaster reported Tuesday that Haines had a leg amputated after suffering serious lower-body injuries.

The attack has shocked Australia’s politicians, with physical violence against lawmakers very rare in the country, and sparked calls for a cooling of recent escalating rhetoric in the public sphere.