Commissioner Lanyon told reporters on Wednesday that the shooting was "completely unacceptable" and now appears to be a case of mistaken identity.
"The fact that what appears to be an innocent life was taken yesterday is something that no community should accept and no community should live in fear of violence," he said.
Emergency services were called to the home in Sydney's south-west about 3:40am on Tuesday after reports of a shooting. Police said multiple offenders broke into the property and shot Mr Tapia, who died at the scene. The offenders fled before police arrived.
The victim was identified as Marco Tapia, an engineering student in his early 20s. His family were home at the time and have been assisting police.
Initially, Acting Superintendent Gretchen Atkins of Campbelltown City Police Area Command described the attack as a "targeted attack." However, a social media post shared by underworld figure Iziah Utai claimed the attackers "popped the wrong person didn't even get the right house." When asked about the post on Tuesday, Superintendent Atkins said everything was being considered.
Commissioner Lanyon's statement on Wednesday confirms the shift in the investigation.
The shooting is the second in as many days and is believed to be linked to organised crime. Commissioner Lanyon said the community could take comfort in the police force's continued and "relentless" efforts against organised crime networks, noting that over the past 12 months, police have arrested over 700 people connected with organised crime.
"I don't want any innocent member of the community to be impacted by organised crime. We will not tolerate it," he said.
Police Minister Yasmin Catley described the shooting as "absolutely shocking" but expressed confidence in NSW Police. A homicide investigation is under way, and the alleged offenders remain at large.