The alleged victim, believed to be about 80, was located with serious injuries beside the Henty Highway, about 300km northwest of Melbourne, at 9.15am on Monday.
Robert Beck, 49, was arrested later that night amid reports an armed man was acting erratically 17km away on Firebrace Street in Horsham.
Beck was interviewed and charged with one count of murder in relation to the man's death.
He appeared before Horsham Magistrates Court on Wednesday morning for a brief filing hearing.
The prosecutor described the case as complex as she sought more time for police to provide the brief of evidence to the defence.
She said there were multiple crime scenes across a large geographical area, with several items seized and multiple phones needed to be assessed.
The alleged victim also sustained 24 injuries in the incident, the prosecutor said.
Beck's lawyer Gemma Ross-McGlynn opposed the longer 12-week time frame, saying it was in her client's interests to have the material as soon as possible.
She instead sought the ordinary six-week period but magistrate Timothy Hoare gave prosecutors eight weeks to provide the brief of evidence to the accused.
Beck remained quiet as Ms Ross-McGlynn told the court he was an Aboriginal man with diagnosed schizophrenia, bipolar disorder and borderline personality disorder.
She asked for a nurse to see the 49-year-old while he was in custody.
Beck was remanded to return to Horsham Magistrates Court for a committal mention hearing in July.
He did not apply for bail.
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