A Launceston jury has retired to consider its verdict in the murder trial of Michael Vernon Lowe.
The 52-year-old has pleaded not guilty to the stabbing murder of Darren Booth in Kings Meadows last year.
In summing up Justice Robert Pearce laid out the case for the jurors citing self-defence as a primary issue in the trial.
The crown alleges the accused murdered Mr Booth in a rage after learning the 37-year-old was in a relationship with a woman that Mr Lowe still loved.
The jury had heard Mr Lowe and Crystal Wells were ``having a break’’ from each other when the alleged murder took place at her home on May 13 2012.
The defence argues Mr Lowe was attacked when he visited Ms Wells unannounced that morning by Mr Booth armed with a cricket stump.
Mr Lowe, of Waverley, admitted using a knife but said he didn’t stab Mr Booth but rather wielded it in front of him, ``jabbing’’ to keep him away.
Justice Pearce told the jury that self-defence could not be relied upon by Mr Lowe if he overcame the threat allegedly posed by Mr Booth before using the knife.
However self-defence was still a defence even if Mr Lowe had started the fight.
Mr Booth was pronounced dead about 2.15am by paramedics after suffering blood loss from a ruptured vein caused by an 8cm stab wound.
Mr Lowe , who suffered a head wound, was interviewed by detectives from Launceston CIB later that day and charged with murder.
Justice Pearce said the jury must also consider a verdict of manslaughter if it finds Mr Lowe not guilty of murder.