Police do not yet have a description of the shooter, but believe more than one person visited the apartment.
Speaking to reporters at the scene, Inspector Paul Robotham said it was «very concerning» that the offender was still on the run.
«Absolutely, this is very worrying for the whole community of Victoria and particularly here,» he said.
«Rest assured, we’ll be doing everything we can to make an arrest as soon as possible.»
The shooting was across the road from the Corpus Christi Aged Care centre, where people have had to move behind police tape to visit their relatives today.
It is also very close to a children’s park in Carlson Reserve, where a group of young people spent the morning training at the sports oval.
Cricketers had to find alternate routes to their game, as the road was closed to traffic.
Al Wong said he played cricket at the reserve most Saturdays. «It’s very, very different from what you’d normally expect in this area,» he said.
«This area is a very family-orientated place. There’s a playground, the tennis club [and] a lot of university students live around here as well.»
Police are still on the scene in Melbourne’s south-east, and are yet to determine the circumstances surrounding the incident. Homicide detectives are combing the apartment for clues.
Courtney Walker lives a few houses away from the crime scene.
«We don’t really speak to the neighbours around here,» she said.
«I didn’t hear a thing last night. I went to the bathroom at 5am, and woke up to knocking at 7am asking, ‘Did you hear anything at 5am?’.»
«I always thought Oakleigh to be quite homely. It just doesn’t feel real. It doesn’t feel like it happened.»
Another local resident, who asked not to be named, said she had heard nothing overnight.
«I’m astonished, absolutely astonished. But these days, you just don’t know,» she said.
«It’s certainly a bit sobering when it happens close to you.»
International students Marshall Cao and Shuya Jia, who live in the city, said they were booked in to see a rental apartment at 11am.
But it is behind the police tape, and the person renting it was not answering their phone.
«We wanted to rent a house here because we will be students at Monash,» Mr Cao said.
Ms Jia said the shooting had scared her. «Maybe we won’t live here,» she said.
Warren Lee, who has been living in Clayton Rd for 10 years, said it was a quiet area.
«It’s very frightening. I didn’t hear anything at all [this morning],» he said.
Another nearby resident Suki Yau said she had just been living here for a few months after moving from Perth.
«It’s pretty shocking someone has been shot,» she said.
Anyone with information should contact Crime Stoppers on 1800 333 000.
Nicole Precel is a video journalist and reporter at The Age. She is also a documentary maker.