Sef Gonzales was born on 16 September 1980 in Baguio City, Benguet, Philippines, to Teodoro “Teddy” Gonzales and Mary Loiva Claridades. His father was a lawyer, while his mother managed the family’s hotel business. In 1983, Sef’s younger sister Clodine was born, completing the family of four. They lived comfortably until the devastating 1990 Luzon earthquake destroyed their home and hotel. The trauma was intense—Sef had to be pulled from the rubble by his father.

This turning point led the family to migrate to Australia, seeking a better life. Settling in Sydney, Teddy requalified as a lawyer, built a successful immigration law practice, and bought land in North Ryde. The family was known for being deeply religious, devoutly Catholic, and traditional in their parenting style. Teddy and Loiva had high academic expectations for their children, particularly Sef. They dreamed of him becoming a lawyer or doctor and weren’t too happy with his passion for singing and music.

Sef attended Parramatta Marist High School and later enrolled in medical science at the University of New South Wales. But two years in, he dropped out and switched to studying law at Macquarie University. He was floundering—failing classes, lying about his grades, and creating forged transcripts to cover up the truth. The pressure was mounting at home. His parents were furious when they found out about the deception—thanks to his sister—and threatened to take away his car, cut him off financially, and possibly disinherit him. Tensions boiled over further when his mother disapproved of his girlfriend at the time.

Police later identified these familial strains, coupled with his obsession over inheritance and material wealth, as key motives that led him down the path of murder.

On 10 July 2001, Sef Gonzales made a decision that would shock Australia. Around 4:00 p.m., he left the family’s law firm where he worked part-time and drove to their home in North Ryde. He was carrying with him a baseball bat and later armed himself with two kitchen knives from their kitchen.

At around 4:30 p.m., he attacked his 18-year-old sister Clodine in her bedroom while she was studying. Sef attempted to strangle her, then beat her with the bat multiple times, and finally stabbed her several times. The autopsy revealed she died from a combination of strangulation, blunt force trauma, and stab wounds.

He waited in the house until about 5:30 p.m. when his mother arrived home. Without hesitation, he stabbed her repeatedly in the face, neck, chest, and abdomen. The attack was so brutal that her windpipe was severed post-mortem.

At about 6:50 p.m., Teddy came home. Gonzales launched at his father with one of the knives, stabbing him numerous times in the chest, back, and abdomen. His father had defensive wounds, indicating a desperate struggle. One stab went through his lung, another hit the heart, and another nearly severed his spinal cord.

After killing his family, Sef tried to fake a robbery-hate crime scene. He spray-painted “Fuck off Asians” on a wall to suggest a racially motivated attack. He disposed of his bloodied clothes, weapons, and even the shoes he wore. After cleaning himself up, he visited a friend and went out for dinner and games in the Sydney CBD, giving himself an alibi. Around midnight, he returned home and called emergency services, pretending to be horrified at the discovery of his murdered family.

The public initially saw Sef as a grieving son. He appeared on TV offering a $100,000 reward, cried during interviews, and gave a eulogy at the family’s funeral—singing “One Sweet Day” by Mariah Carey and Boyz II Men. But investigators quickly noticed inconsistencies in his story and behavior.

He visited the family’s accountant asking about his inheritance just days after the murders. He attempted to buy a Lexus and pawned family valuables. Police became suspicious and began surveillance. His internet searches revealed he had researched poisons, even ordered toxic plant seeds, and drafted letters falsely accusing others. He also faked an email and staged a failed burglary to deflect suspicion.

The major break came when his alibis fell apart, including one where he claimed he went to a brothel. None of it added up. His fingerprints were also linked to anonymous product poisoning threats, and paint on his clothes matched the graffiti on the crime scene wall. On 13 June 2002, police arrested Gonzales.

The trial began in April 2004. Prosecutors presented him as a manipulative, selfish young man who had planned the murders for months. The court heard of his lies, his failed academic record, and his motive: fear of being disinherited and a desire to access over A$1.5 million in inheritance. On 20 May 2004, Sef Gonzales was found guilty of three counts of murder and one count of threatening product contamination. He received three concurrent life sentences without parole.

Justice Bruce James called the crimes “heinous” and stated there were no mitigating factors.

Gonzales attempted to appeal in 2007 and again in 2018, 2019, and 2021—all efforts failed. He remains in prison in New South Wales.