Police say they view Danny Klobucar, 25, as their "main suspect" over the death of Miodrag Gajic, 71.

They have also revealed they are investigating Klobucar over a similar attack, in which a victim was severely beaten in his own home almost a month earlier.

Homicide detectives told the court that victim now fears for his life, and believes Klobucar will come back to ‘‘finish the job’’ if released.

Mr Gajic was found dead on the floor of his Mansfield Place unit by friends.

The elderly, frail man had sustained significant head injuries in an attack that police believed happened several hours earlier.

Fairfax Media revealed last month that a suspect in the killing was no longer at liberty, after being arrested for a series of other, unrelated offences.

That suspect, Danny Klobucar, made a bid on Friday to be released on bail on those separate offences, which relate to property damage and threats to fight staff at the Lighthouse pub in Belconnen on the night of the murder.

Klobucar is currently facing a string of 15 charges, including the new alleged offences relating to the Lighthouse disturbance.

He was arrested at the pub on the night of the murder, and police have since raided his grandfather’s home in Chapman, and are still searching the Mugga Lane tip for a bloodied shoe they believe he was wearing after the murder.

Police told the court that search could continue for the next four weeks.

Klobucar spent about a month at the Canberra Hospital’s psychiatric unit receiving treatment, before being transferred to the Alexander Maconochie Centre.

His lawyer Michael Kukulies-Smith said his client had changed markedly since the treatment, and any risk he posed could be managed by bail conditions to report to police and submit to drug and alcohol testing.

Police admitted under Mr Kukulies-Smith’s cross-examination that Klobucar had been ‘‘very polite’’ and cooperative in their recent dealings with him.

Mr Kukulies-Smith said police appeared to be attempting to detain Klobucar without charge to allow them to continue investigations into Mr Gajic's death, something which the court should not allow.

‘‘If there is sufficient material to lay the [murder] charge, then it ought to be brought, not left in this speculative state,’’ he said.

He said the current charges that Klobucar faced all gave him a presumption in favour of bail.

But Magistrate Peter Dingwall said the risk that Klobucar would not return to court was too great, given the seriousness of the charges he knew he faced.

Mr Dingwall said he feared Klobucar may try and flee the territory, and may reoffend.

He was denied bail and remanded in custody until March.

Detective Constable Jarrod Dunbar told the court police would charge Klobucar with murder, likely during his next court appearance on March 27.

The homicide detective said Klobucar had threatened to come back and kill the Lighthouse staff.

He said police held ‘‘genuine fears’’ that Klobucar ‘‘certainly has the capability to return there and carry out his threats’’.

Police said they had no confidence that Klobucar would abide by his bail conditions, and feared he may flee and take refuge with relatives interstate.

Mr Gajic was a cannabis dealer and was known to police.

But he was also a loved father and grandfather whose family remembered him as a kind-hearted, funny, and devoted man.

Mr Gajic was known for the love of his little Maltese terrier, Minda, and was regularly seen by neighbours taking it for twice-daily walks.

He was frail and had been unwell for some time.