A 77-year-old man has been left with multiple injuries after being allegedly attacked by a stranger wielding a "large tree branch".
On Saturday, a magistrate described the alleged daylight assault as "bizarre in nature" and "unprovoked violence".
The 39-year-old alleged offender, whom The Canberra Times has chosen to not name, did not enter a plea to assault occasioning actual bodily harm when he faced the ACT Magistrates Court.
He did not apply for bail after initially indicating he would do so.
According to police documents tendered to the court, the Hughes man began chasing the alleged victim on Friday afternoon in Belconnen.
The alleged offender is accused of picking up an approximately one-metre long tree branch during the chase and is said to have repeatedly struck the elderly man, who was yelling out: "Help me."
Police claim the alleged victim fell forwards onto his hands and face as a result of being struck by the branch while being chased.
The accused man is said to have struck the 77-year-old man on the ground four more times to the back of his head and neck.
The alleged assault only stopped when another man intervened, documents state.
Images tendered to the court show the alleged victim's numerous injuries, including several bruises and grazes to his back, shoulders, cheek, arms, stomach and hands.
He is said to have been bleeding from his face.
A prosecutor said the alleged offending was "so inexplicable" it was difficult to see how any bail conditions could mitigate possible risks.
The court heard there were concerns for the alleged offender's mental health.
Magistrate Glenn Theakston said the man needing a mental health assessment was clear but "not the only consideration".
Mr Theakston refused to send the man for an assessment after telling parties he was not confident the "violent offender" could be kept in a hospital.
The alleged offender was marked as a "prisoner at risk".
