Victorian police are turning to the public for information following the "suspicious death" of a man who was fatally shot and buried in the state's north-west.

Richard Wills, 65, was last seen leaving his home on Hughs Street in Ouyen at about 8am on Sunday, April 5, as part of his usual routine.

Police were told that he was leaving for work on his rural property on the Mallee Highway.

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Suspicions arose, and his family members began searching the property after he did not return home for lunch.

His wife reported him missing the following day, after he still had not returned.

Police began searching the property, and Wills' body was found at about 1.30pm on April 7.

He had been fatally shot and buried in a "shallow grave" on his farm.

Detective Senior Sergeant Steve Trewavas from the missing persons squad said that he was "clearly met with foul play".

READ MORE: Top Democrat demands Donald Trump submit to a dementia test

"What is still unclear is exactly who was involved, and why," Trewavas said.

"We're hoping that this appeal leads to someone coming forward and doing the right thing, it can be done anonymously, so that we can hold those responsible to account."

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One of the most prominent Democrats in Congress has written to the White House doctor demanding Donald Trump take a cognitive test.

Representative Jamie Raskin wrote to Sean Barbabella expressing his concern at the president's condition.

"Experts have repeatedly warned that the President has been exhibiting signs consistent with dementia and cognitive decline," he wrote.

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"And, in recent days, the country has watched President Trump's public statements and outbursts turn increasingly incoherent, volatile, profane, deranged, and threatening.

"His apparently deteriorating condition has caused tremendous alarm across the nation (and political spectrum) about the President's cognitive function and continuing mental fitness for the office and President."

Raskin requested a comprehensive cognitive test, with the results to be shared with Congress.

He cited Trump's bizarre and profane social media post on Easter Sunday in which he threatened to destroy Iranian civilian infrastructure, dropped the F-word and praised Allah.

""Open the F—in' Strait, you crazy bastards, or you'll be living in Hell — JUST WATCH!" he wrote.

"Praise be to Allah."

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Raskin also mentioned the apparent difficulty Trump had in descending the White House steps that day.

He drew attention to how top Republican congressman James Comer subpoenaed the White House physician during the last administration for information on the cognitive capacity of Joe Biden.

Biden, like Trump, faced numerous questions about his mental faculty in office. Trump is now the same age Biden was at this point of his presidency.

A White House spokesperson issued a statement to Courthouse News criticising Raskin.

"Lightweight Jamie Raskin is a stupid person's idea of a smart person," the spokesperson said. 

"President Trump's sharpness, unmatched energy, and historic accessibility stand in stark contrast to what we saw during the past four years when Democrats like Raskin intentionally covered up Joe Biden's serious mental and physical decline from the American people."

Raskin's demand comes as several prominent conservative commentators have called for the cabinet to invoke the 25th amendment.

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The 25th Amendment would require the vice president and a majority of the cabinet to determine the president is not able to do his job.

Congress would then have 48 hours to vote in support. It would take a two-thirds vote in both chambers to remove Trump.

InfoWars commentator Alex Jones said Trump was no longer fit to hold office.

"How do we 25th Amendment his ass?" Jones said.

"Trump literally sounds like an unhinged super villain from a Marvel comic movie."

Trump has taken several cognitive tests in the past year, and has frequently bragged of the results.

Those tests are normally conducted in order to determine if a person has dementia.

Raskin is the ranking member of the House Judiciary Committee, and rose to public prominence during Trump's second impeachment trial as well as the investigation into the January 6 insurrection.

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A driver has been arrested and taken to hospital after allegedly striking a group of motorbike riders in Sydney's south-west overnight.

Police were told that at about 8.30pm a Holden Cruze Sedan had hit a group of motorbike riders who were waiting at an intersection of the Hume Highway and Johnson Road in Bass Hill.

The 49-year-old man drove away but was allegedly assaulted at a nearby Speedway petrol station in Bass Hill by several of the motorbike riders.

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Shocking footage showed the ordeal and the moment the car mowed down the group of dirt bike riders, with a separate video also showing one of the riders repeatedly jumping on the hood of the car.

A group of motorbike riders was seen swarming a Speedway petrol station in Bass Hill before one of the riders was spotted repeatedly jumping on a car.

In a second video, a car is seen mowing down the group, with at least one rider seen falling off their bike and onto the road.

9News understands the group of riders are the same in both videos.

READ MORE: Police appeal for information after Victorian man, 65, fatally shot and buried in state's north-west

The driver left the petrol station and drove to a nearby shopping centre car park, where he crashed into a fire hydrant. He then fled before police arrived.

Following investigations, the man was arrested at about 9am today at an address in Bass Hill.

He was taken to Bankstown Hospital under police guard for treatment of facial injuries and a possible fractured arm.

Police are continuing to investigate the incident.

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The US-Israeli war in Iran, Iran's retaliation across the Middle East, Israel's war in Gaza, Russia's invasion of Ukraine and the conflict in Africa: It's not hard to see why many are concerned about the potential for another world war.

After World War II ended in 1945, countries established the United Nations to prevent future conflict and promote peace.

For a while, it worked.

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But now as world leaders defy the UN's recommendations and military security alliances such as NATO stand on shaky ground, post-war peace strategies are coming into question.

Adding to concerns of a potential World War III, are US President Donald Trump's escalating threats against Iran and Iran's retaliation across the Middle East keeping the war, which started on February 28, simmering. 

However, whether we actually are headed towards another world war, from a technical point of view, is more nuanced.

What is a world war? 

There is no clear definition of what constitutes a world war.

The United Nations does not have one, but here is how some dictionaries define it:

• Oxford: "A war involving many nations of the world"
• Cambridge: "A war in which large forces from many countries fight"
• Merriam-Webster: "A war engaged in by all or most of the principal nations of the world"

David Kilcullen, who served in the Australian army for 22 years and worked as a diplomat for almost 30 years with both the Australian and US governments, said a world war usually involves overlapping conflicts and countries.

"When you get multiple campaigns, usually in different continents, Europe, Africa, the Middle East, Asia, and you have all the same combatants fighting in multiple campaigns at the same time in different continents, that's definitely a world war," he said.

READ MORE: 'Fundamentally ignorant': Outrage over Abbott's calls to join the war

How close are we to another world war?

Kilcullen said there is a potential for the conflict to expand into a world war if it connects with the Russian invasion of Ukraine or if China or North Korea use the situation as an opportunity to further their own agendas in Taiwan and South Korea, respectively.

But he noted that we usually don't know we're in a world war until after the fact.

"It's been in the eye of the beholder," he said.

"If you think of World War II in retrospect, that looks to us like a world war, but at the time… it was really just a European war.

"It was only when Hitler invaded Russia and then the Japanese attacked the US that suddenly it went from being a European war to being a world war."

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Billionaire investor Ray Dalio, who said he has spent the last 50 years studying global events that affect markets, laid out his 13 steps to a WW3 in his latest newsletter.

He said the world is alreadt at step nine, which is when several multi-theatre conflicts happen simultaneously.

Step nine is followed by countries demanding internal support for war, direct military combat between major powers, a big increase in taxes and debt with some markets shutting down, and finally one side winning the war against another.

"Virtually nobody is talking about the fact that we are in the early stages of a world war that isn't going to end anytime soon," he said in a social media post. 

What would a world war mean for Australia? 

Australia has deployed military assets in the Middle East to defend citizens and civilians.

Prime Minister Anthony Albanese this week signed off on keeping the E-7A Wedgetail in the region "a period of time", but reiterated that Australia was not involved in any offensive capacity.

While Australia is geographically placed away from the global conflicts, Kilcullen said it would be unable to distance itself fully from a world war due to its dependencies on global trade.

READ MORE: Iran war to permanently scar global economy even if peace is reached: IMF

"And that's the reason we've always tried to have a big ally, originally the British and then the Americans," he said.

Kilcullen added that Australia could be in even more trouble if China ever decided to invade Taiwan.

"That would be even worse, because we would definitely be in that war one way or another," he said. 

"The timeline that most people think is likely for a Chinese move on Taiwan could be as soon as next April, so we could be in the last 12 months before a really, really major conflict."

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Aussie retailers are reporting an unprecedented surge in bike sales as commuters ditch their cars to bypass the fuel pump.

As tensions in Iran disrupt global energy markets, the ripple effect is now showing up in how we choose to get around.

99 Bikes has recorded a staggering 136 per cent increase in sales over the last week alone – a trend consistent across every state.

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Unlike the COVID-19 bike boom, which was largely driven by boredom and the urge to escape the house, this time, it's different.

"We've seen a clear shift for people as bikes, e-bikes and e-scooters become a solution to the rising cost of fuel and a long-term cost of living fix," says David Miller-Heidke, General Manager of 99 Bikes.

At Decathlon Australia, the data tells a similar story.

Head of Digital Antoine Vaxelaire reports that online orders in the cycling category have jumped 50 per cent year-on-year in just the last fortnight.

He notes that cycling is increasingly viewed "not just as a sport or leisure activity, but as a smart, everyday response to rising fuel costs."

For many, the move isn't about buying a new toy, but replacing a second family car.

Sydney dad Jerémie Siguan recently invested in a bike for his three-year-old son Django's daycare runs.

"I've always loved cycling for leisure, but it never crossed my mind as a practical, everyday solution – the fuel crisis changed that thinking pretty quickly," he tells nine.com.au.

"We needed something that could replace the car for day-to-day life, not just the occasional weekend ride."

The Bronte local says the switch from car to bike has also led to a new routine.

"There's something that just feels better about being out in the fresh air and moving, rather than sitting in traffic. It's also given us genuine quality time together, something we didn't expect but now really value," he adds.

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When it comes to e-bikes, while the savings in fuel are immediate, the upfront cost often ranges from $5,000 to $10,000.

As a result, subscription services have seen a 15% spike in inquiries in recent weeks.

Katrina Khao, Head of Marketing at Lug+Carrie, says the service is effectively "recession-proofing" household budgets in Melbourne, Sydney, and Brisbane.

"Over the last five years, our users have collectively saved an estimated $1 million in petrol costs by swapping car trips for Lug+Carrie e-bikes," Khao says.

As the cost of living tightens its grip, the humble bicycle is proving a popular way to commute. For those still paying $2 plus at the pump, the message from the bike path is simple.

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"The fuel situation might be what first gets you thinking about it," Siguan says.

"But once you start riding, you quickly realise the benefits go well beyond just saving money."

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