A notorious teen offender killed in a horror crash in an allegedly stolen ute over the weekend has been remembered as a “precious” and “beautiful young man” by his family.

Conroy, 14, died after the allegedly stolen vehicle he was travelling in smashed into a tree on the Calder Highway at Woosang, 240km north-west of Melbourne, on Saturday morning.

Conroy was well known to police and had previously been granted bail for multiple offences.

His cousins, Dougie, 18, who was driving, and Deondre, 14, are both fighting for life after being cut from the ute and airlifted to hospital. Dougie has lost the lower part of his right leg and suffered broken ribs and a brain bleed, while his younger brother Deondre remains in ICU with serious brain injuries.

Police allege the ute was stolen from a hotel in Mildura on Friday night. Seven hours later, it was involved in a fuel drive-off. Shocking footage has also emerged showing the group of teens hanging out of the windows of the swerving vehicle moments before it crashed into the tree, with their bodies almost entirely outside the ute as friends filmed the stunt.

Conroy’s mother told 7News she does not want her son’s death to be in vain.

“We’ve tried so hard to keep Conroy on the straight and narrow and to keep him out of trouble,” Chereeta Wightman said. “He was a fun-loving, outgoing, good-spirited kid.

“(Dougie) will have to live with what he’s done. I feel for him. I feel for all of them.”

Aunty Maryanne Frost added: “Yeah, they made the wrong choice, but people shouldn’t go judging them… if people actually knew these boys’ story and what they went through growing up, they would understand.”

The family also warned other teenagers to think carefully about their actions.

“It just takes one little mistake and then your family’s suffering, and we gotta go through the pain of burying you,” Ms Frost said.

In online tributes, Conroy’s family members described him as a “beautiful soul” who loved helping look after their children and putting smiles on people’s faces.

One woman wrote: “I told you the only person in Mildura I had was you Conroy. I told you my babies had no one but you… I told you that no matter what I love you unconditionally. I told you I’ll hold you through thick and thin.”

Detective Sergeant Pendrick said investigators were working to determine how fast the allegedly stolen car was travelling at the time of the crash.

“There was certainly a high impact with the tree, there’s no doubt about that,” he said.

“We look at everything. We’ll look at speed, we’ll look at the road condition, we will look at the manner of driving.”

The detective said crashes like this served as a reminder for young people to understand there are consequences for their actions.

“When you look at incidents like this that are totally devastating, you just plead with those kids that they’re not playing games, there are real consequences,” he said.

Shadow police minister Brad Battin criticised the Jacinta Allan Labor government hours after the crash, saying similar incidents were preventable if authorities took a tougher approach to youth crime.

“We need to fix the justice system,” he told the Herald Sun. “Releasing young offenders for stealing cars and having unlimited bail not only leaves the community less safe, but we will see more young people die.

“What will it take for the premier to stand up and say enough is enough? Break bail, face jail. I am sick of a government that simply doesn’t care.”

An Allan government spokesperson hit back, accusing the opposition of using the tragedy to score political points.

“Our thoughts are with the young people’s loved ones as they deal with the loss and injury caused by this senseless act,” the spokesperson said.

“Politicising a teenager’s death says everything you need to know about (Victorian Opposition Leader) Jess Wilson, whose first instinct is to send out her conspiracy theory-peddling shadow.

“There are no easy solutions to youth crime, but community safety comes first, which is why we’ve introduced Adult Time for Violent Crime to deliver serious consequences for repeat offenders.”

The new reforms mean children aged 14 and over now face the adult court system and can receive the same sentences as adults, including life imprisonment in certain cases.