A man accused of killing three family members with a hammer and seriously injuring another in an alleged drug‑fuelled attack was a Hillsong Church devotee who said he struggled to connect with others.

Jacky Amazing Feng, 32, allegedly used the weapon to bludgeon his mother, Ruvena Lam, his father, Zhou Chao Feng, and his younger brothers, Jason Feng, 30, and Justin Feng, 25, at their Rosemeadow home in southwest Sydney after 1.30am on Sunday.

The only survivor was Jason, who managed to call emergency services before being taken to hospital.

Feng initially fled the scene but was arrested when he returned to the house in a silver Subaru at 2.30am. He was charged with three counts of murder and one count of attempted murder.

He was due to face Campbelltown Local Court on Monday. It is understood he was allegedly under the influence of drugs when the situation unfolded. 

The Daily Mail can now reveal Feng was using social media to share his Christian beliefs, with his last post on April 6 - just four weeks before the alleged killings.

His last post was a response to a video called 'how you know someone is evil.' He wrote: 'It's not always easy to tell - there are dangerous people out there, not everyone gets along with each other.'

He also used social media to share his opinions on narcissists, sin, and domestic violence, to encourage others to attend Hillsong Church and practise mindfulness, and claimed to have abstained from sex by masturbating for hours at a time.

Feng began commenting on social media in March 2025, but the highest concentration of posts occurred between October 2025 and April 2026.

In November, he responded to a social media user who urged others not to 'make masturbation feel like something guilty'.

Feng said he had practised 'gooning' - prolonged masturbation sessions where orgasm is deliberately delayed for hours.

He said: 'I've been gooning for 10 years through dramas connecting with other people, it can sometimes be better not to have sex, I find it difficult to take care of myself and don't want to burden others.

'Social pressures of competitiveness, being able to be honest, without argumentative explosions, once you start falling behind, you can't be around stable people anymore.

He added: 'That's life, the strong live and the weak die.'

In response to one user who was upset about being alone at 40 with no accomplishments, Feng wrote: 'Go to a Christian church - I'm going to Hillsong at the moment so that is what I recommend.

'Find brothers and sisters that won't judge you too much.'

Responding to one person who asked how to survive rock bottom, Feng said: 'You must accept yourself for how you react and respond to the world. Failure is another step towards growth.

'Be aware of the environment you are in and have experienced.'

Another person chastised some pastors for failing to teach their community about the harms of physical and emotional domestic violence.

Feng said some pastors do talk about domestic violence, but others may not be equipped to deal with it. He said it was best for church leaders not to be overconfident about the issue or to avoid it entirely.

Someone else asked whether marijuana consumption was a sin, to which Feng said 'almost everything can be a sin' and referenced lying, fighting over food and water, and judgment.'

The Fengs' five-bedroom Rosemeadow home remained cordoned off by police on Monday.

Property records show they bought the home in 1998.

Family friends told the Daily Mail on Monday they were shocked to hear about the tragedy, including Jishnu who studied engineering with Justin at the University of Sydney. 

'Justin was a kind person who I enjoyed spending time with,' he said.

'He was a sweet person and a good friend he will be missed greatly.'

Justin was also described as the 'smartest guy' by a high school friend.

'RIP to Justin and his family,' he wrote.

'Went through school together, was always a bright guy, smartest guy as well, gone too soon.'

Emergency services were confronted by a 'very grisly crime scene' when they arrived at the property in the early hours of Sunday morning.

Campbelltown Commander Superintendent Grant Healey said: 'Police first encountered a 65-year-old woman and started doing first aid on her.

'Police went inside the house and found a 64-year-old male who was still alive with serious blunt force head injuries.'

'They found a male deceased in a granny flat at the rear of the premises.'

He said the family were not known to police and described the situation as 'a very tragic incident'.

Police believe more than one weapon was used during the alleged attack - one that would cause 'blunt force trauma', as well as a 'bladed weapon.'

'Police were confronted with a very bloody scene,' Superintendent Healey said.

'Blunt force trauma is always horrendous for people to confront, and any edged weapon attack is horrendous to confront, so police and ambulance did a fantastic job in very trying circumstances.'

On Sunday, shocked neighbours said the family mainly 'kept to themselves.'

One neighbour, who knew Jacky Feng, said ambulance crews had attended the home several times in the past year.

Another neighbour said he was awoken at 1.30am by what he thought was 'a car chase'.

'Then all the emergency cars came and a silver Subaru returned to the street. Someone said they saw a man hold up his hands as police approached him,' he said.