A man believed to be visiting another house was shot dead just as he entered the doorway in what police fear could be the second mistaken identity attack in Sydney this week.

The man in his 40s was gunned down in a drive-by hit at a home in Merrylands West, western Sydney, about 3.15pm on Wednesday.

He had arrived as a visitor to the home just minutes earlier with a male resident and two young children, who were likely returning home from school.

Detective Superintendent Simon Glasser told reporters the children were inside the home when the shots rang out.

The home owners were “very well known” to police for links to organised crime.

But Glasser said the victim, who had no known criminal history, was likely a business associate.

“It’s very early on in the investigation, however tragically that is a possibility that the wrong person has been shot by these offenders,” he said.

The drive-by attack was on Bruce Street, West Merrylands. Photo: AAP

The Daily Telegraph reports that the victim was Joshua MacDonald, 40, who had just parked a work vehicle in the driveway and walked to the front door.

Gunmen in a stolen grey Audi sedan opened fire with a volley of “four or five” shots, with one bullet striking MacDonald in the head and killing him instantly, reports the Telegraph.

Police have launched an investigation and are searching for a grey Audi sedan captured on CCTV leaving the scene westbound on Bruce Street.

News Corp shared footage showing shots being fired from a vehicle as it was driving past.

“There are a number of schools in the vicinity, a number of parks. This is a highly dangerous and reckless act that’s been carried out here on a public street,” Glasser said.

Officers on the scene after the shooting on Wednesday afternoon. Photo: AAP

It comes after multiple attackers were believed to have forced their way into a two-storey home in Glen Alpine, near Campbelltown in southwest Sydney, about 3.40am on Tuesday.

They then shot 23-year-old Marco Tapia dead in his bed as his family slept.
NSW Opposition Leader Kellie Sloane said the incident showed gangland violence was once again out of control.

”We need to be very clear about the threat on our streets and that is dangerous organised criminals … innocent people have been in the firing line way too often,” she said.

”Whether it is a young man, a student sleeping in his bed at night (or) a grandfather who’s kidnapped and murdered.”

Marco Tapia was killed in his bed. Photo: LinkedIn

She suggested the government was not doing enough to stop the shootings.

But Police Minister Yasmin Catley criticised the east Sydney-based MP’s position on the state’s gun buy-back scheme, launched after December’s Bondi massacre.

”The member for Vaucluse, we must remember, is also the same person that wants to squash (national gun buy-back reforms),” Ms Catley said.

”She wants more guns on the street and wants to blame the police for not doing their job … I’m not tolerating that, I won’t have a bar of that.”

NSW Greens leader Sue Higginson told AAP the tragic death was an awful reminder of the danger of guns in the community.

”This instant and irreversible act of gun violence that killed Marco Tapia this morning was only possible because guns are still accessible in the community,” she told AAP.

Glen Alpine has one firearm for every 16.7 residents, she noted.

Tapia’s killers were at-large more than 24 hours after the savage home invasion.

The young man was not known to police and had nothing more than a traffic offence on his record.

Detectives are considering his death could be the result of a mistaken identity hit.

Tapia’s martial arts gym remembered him in a public tribute overnight.

”We lost a real one today,” they wrote, adding ”rest easy Marco, one of us forever”.

An exiled alleged underworld identity posted to social media early on Tuesday that the perpetrators had mistaken their target.

”Popped the wrong person. Didn’t even get the right house,” Iziah Utai, alleged co-founder of the Coconut Cartel, wrote.

He returned on Wednesday to add: ”RIP Marco. #innocentvictim”.

The Alameddine network, a notorious crime family, and the Coconut Cartel, an emerging crime-for-hire network, have allegedly become embroiled in a feud, spilling into shootings across Sydney in recent months.

Campbelltown Acting Superintendent Gretchen Atkins on Tuesday said she was aware of online posts and said everything was under consideration.

-with AAP