Alien fear led undie-clad man to carjack woman, bite cop, court told

Wearing only undies and ECG dots, Benedict Kearney carjacked a woman, sped down the wrong side of a road and then bit a policeman who tried to arrest him.

He'd been an ice user for two decades, but this was his first time in a drug induced psychosis and he feared aliens were after him.

Deeply ashamed, sorry and behind bars, he's committed to getting help so it doesn't happen again.

He wound up in hospital on July 15 last year after being found unconscious in a Melbourne park.

He'd combined ice with Xanax for the first time and believes the anxiety drug was the problem.

A nurse spotted him leaving the emergency department of a Werribee hospital in his underwear with four heart test dots still stuck to his chest and blood on his hands.

Minutes later a woman leaving work got in her car. Kearney appeared beside her.

"I want your car. I need your car. Get out of the car," he told her. He said he didn't want to hurt her, but needed to get away from "these idiots".

She panicked and refused. He yanked for her keys, fracturing her finger, and punched at her hand. She jumped in the back seat as he took the wheel.

The 37-year-old father of four did burnouts and sped laps around the hospital car park looking for the exit.

Police blocked the driveway so he drove over flowerbeds to reach the road, speeding down the wrong side and overtaking cars at twice the speed limit.

His erratic driving ended when he collided with a traffic island, throwing the victim from her seat.

The car went off the road, through a fence and became wedged in a ditch.

Undeterred, the victim tried to stop Kearney fleeing the scene by grabbing his arm. He pulled away and was spotted by police walking out of bush a short time later.

He resisted arrest, punched at an officer and bit another before they put him in the back of a divvy van, which he then damaged with aggressive kicks.

The victim needed surgery for her broken finger and will never regain full use. She's suffered flashbacks and fear after the incident, which affected her confidence.

Kearney admitted his crimes, pleading guilty to charges including carjacking, recklessly causing serious injury and assaulting police.

He remembers waking in hospital with "aliens looking over me" and of running away from "horror characters" and stealing the car, but recalls nothing of his interaction with the victim.

Kearney felt enormous shame and remorse, and was taking responsibility for his actions, County Court Judge George Georgiou said on Friday.

He's done every program possible behind bars, has lined up work after his release and will be supervised by family to help his drug and alcohol abstinence.

Kearney must serve at least 20 months of a three-year sentence.

If you or anyone you know needs support call Lifeline on 131 114, or Beyond Blue's coronavirus mental wellbeing support service on 1800 512 348.

AAP