Five people are facing trial accused of murdering Bobby Medcraft, 23, who died from blood loss following an altercation in the northwest city of Burnie in the early hours of March 29, 2020.
Cody Christopher Shane Sheehan, 33, Michael William Hanlon, 54, Geoffrey James Deverell, 37, and siblings Kelsey Maree Ford, 24, and Lucas Shane Ford, 31, have pleaded not guilty.
Crown prosecutor Jack Shapiro said Mr Medcraft was attacked by three of the men in a suburban street and ended up on the ground where he was repeatedly kicked and punched.
He was allegedly "chopped" with a sword on the back of the leg by Sheehan, severing his major artery and hamstring, and later died in hospital.
"With that weapon, it was an injury that was likely to lead to death," Mr Shapiro told the Supreme Court of Tasmania in Launceston during opening submissions on Tuesday.
He indicated tensions sparked when a friend of Mr Medcraft mistakenly sent a Snapchat message to Lucas Ford with the phrase "what up c***".
Mr Shapiro said abusive messages between several people ensued, resulting in two groups, one including Mr Medcraft, being separated by police outside a house.
"At that point from (Mr Medcraft's) perspective, the night was really over. We allege that the night was not over (for the accused)," Mr Shapiro said.
"The accused agreed they would find (Mr Medcraft) and inflict violence as an act of retribution, revenge."
Mr Shapiro said there was a car chase involving the two groups in which Mr Medcraft's car was struck with a cricket bat.
Kelsey Ford, who allegedly drove a car in the chase, then videoed "a gratuitous attack" on Mr Medcraft.
Lucas Ford, Hanlon and Sheehan began punching and kicking Mr Medcraft while Kelsey Ford and Deverell prevented people from helping him, Mr Shapiro said.
He told the jury the five accused had united in an "unlawful common purpose".
"One punch can kill. Agreeing to attack someone … murder is a probable consequence," he said.
Sheehan's lawyer, Greg Richardson, told the court Mr Medcraft had earlier threatened to stab Lucas Ford in the face, and an axe and knife were found in the car he had travelled in.
He said Lucas Ford and Deverell had been stabbed with what appeared to be broken bottles during the altercation and urged the jury to consider self-defence.
Lawyers for Deverell and Kelsey Ford said neither of their clients put a hand on Mr Medcraft.
The trial, which is expected to run for several weeks, continues.
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