Homicide detectives are investigating the possibility a teenager executed a Phillip man in his doorway in a case of mistaken identity.
Police revealed that line of inquiry on Monday after charging an 18-year-old man with the late night shooting murder of Glenn Walewicz, who was gunned down when he answered the door to his public housing unit last June.
The alleged killer, who cannot be named because he was a juvenile when the murder occurred at Connorville Gardens, is now behind bars on remand.
Wearing a black puffer jacket, grey tracksuit pants, white sneakers and a white face mask, he stood silently in the ACT Children's Court on Monday as magistrate Jane Campbell read to him two charges.
He did not enter pleas to a murder charge laid over the death of Mr Walewicz, 48, or an affray allegation stemming from an incident last month.
Defence lawyer Tich Pasi said the teenager, who was supported in court by his mother and sister, was not applying for bail.
Ms Campbell, who noted the presence of Mr Walewicz's mother in the court's public gallery, accordingly remanded the young man in custody.
The 18-year-old was apprehended at his suburban Belconnen home on Sunday, hot on the heels of alleged co-offender Reatile Ncube being refused bail.
Ncube, 19, was arrested on Friday evening and charged with being an accessory after the fact to murder after police intercepted phone calls in which he allegedly discussed plans to "get rid of" two shotguns.
The Dunlop man also allegedly told a friend he needed to "make some shit up" after learning police wanted to speak to him about what his car had been doing in the vicinity of the murder.
Prior to court commencing on Monday, Detective Inspector Mark Steel said ACT Policing was confident Mr Walewicz had not known either teenager.
He said one possibility, which remained under investigation, was that Mr Walewicz was not the intended target of the shooting.
"We're looking at all avenues," the senior investigator told reporters at a press conference outside City Police Station.
Detective Inspector Steel said homicide detectives had identified the alleged killer and Ncube through "good old-fashioned police work", which had included "hitting the ground, speaking to witnesses [and] canvassing for CCTV footage".
He added that very little information had been forthcoming in the early stages of the year-long probe, which had initially been "a real whodunnit".
Detectives had trawled through hundreds of hours of footage, he said, and analysed mobile phones as part of the ongoing investigation.
"It's certainly testament to the tenacity and dedication of all [police] members involved, from those homicide detectives through to our support areas," Detective Inspector Steel said.
The senior investigator, who described the alleged killer's age as "quite shocking", signalled further arrests were likely.
"It's an opportunity now for those that are involved to come forward and speak to police," he said.
Anyone with information on the matter has been urged to contact Crime Stoppers on 1800 333 000, or via the Crime Stoppers ACT website.
The 18-year-old alleged murderer is due to front court again on June 27, while Ncube is scheduled to make his next appearance in the ACT Magistrates Court a week before that.
