Accused murderer Simon Peter Carman spent much of the past decade isolating himself from many of his friends and family in Australia, according to those who knew him.

The ABC understands Mr Carman had little contact with his parents and siblings, and preferred to spend his time in Thailand, where he’s been living since late last year.

It’s in his room in the city of Pattaya — a city known internationally for its red light district — that Thai police allege a gruesome murder occurred.

The ABC understands Mr Carman remains in detention in Pattaya Prison, and is waiting for local police to complete their investigation before he appears in court.

Country background

The 45-year-old Australian was born in Victoria but raised in Western Australia.

People who knew Mr Carman have told the ABC he grew up in the small southern regional town of Jerramungup, and moved to Albany on the south coast with his family as a teenager.

He drove trucks for a while but suffered a workplace injury that led him to take pain medication, which he came to blame for his weight gain.

His family did not want to talk, but the ABC understands it was around this time that Mr Carman isolated himself from his family, and from many of his friends in WA.

“When people cut themselves off from people, well, it’s not a normal thing to do,” one family friend said.

WA Premier Roger Cook said Mr Carman had “various interactions” with police while he lived in WA, including having his firearms confiscated.

Court records show his gun licence was suspended in 2023, and he tried and failed to get it back.

It is understood Mr Carman frequented Thailand before the COVID pandemic, but returned to Australia during the outbreak.

He was last seen living in Australia in a unit of a commercial complex in an industrial area of the southern Perth suburb of Rockingham.

His social media history in the year before he travelled back to Thailand was filled with both complimentary and disparaging comments on pictures of women, in some instances asking where they lived.

Life in Thailand

Mr Carman travelled to Pattaya again late last year, where he is understood to have remained since.

Last week, on June 26, police received reports that 17-year-old Tunchanok Donhomla was missing, after last being seen getting picked up on the Beach Road vice strip by a foreigner.

Officers traced the teenager’s movements to Mr Carman’s room. But neither was there.

Mr Carman was arrested at Bangkok’s Suvarnabhumi Airport as he tried to board a flight back to Australia, with scratch marks on his neck and arms noted by arresting officers.

But Ms Tunchanok was still missing. CCTV would prove critical, capturing Mr Carman leaving his room the previous night with a heavy suitcase, then returning without it about half an hour later.

Police found what they allege to be the same suitcase dumped near a train track, about a 10-minute drive away from Mr Carman’s building.

Inside was the 17-year-old’s body, curled up and stuffed alongside her clothes and other belongings, police said.

Ms Tunchanok’s family said her face was bruised and swollen, and she had broken teeth.

A partial confession

Surrounded by Thai police, Mr Carman was quizzed about what happened.

Initially he denied any wrongdoing, claiming Ms Tunchanok “disappeared from the room while I was asleep”.

But as the evidence mounted against him, police said Mr Carman confessed to killing the teenager.

Nonetheless, the 45-year-old has denied the charges of murder, concealing a body, moving or destroying a body, and taking a minor for 𝘴єxual purposes.

Police said Mr Carman claimed the teenager threatened him after a dispute over money.

In a recorded message to Ms Tunchanok’s family, Mr Carman said the girl’s dєatᩚh was “out of my control”.

“I know you’ll be very sad, upset, same same me,” Mr Carman said, mimicking a common phrase used by Thai people speaking English.

“I hope you’re OK, I know you’re not, but I hope. And please tell other girls to be, just to be careful.”

The family is pushing for the dєatᩚh penalty if Mr Carman is found guilty.

Night of the alleged murder

Affectionately known as “Cake”, Tunchanok Donhomla had travelled from her home town of Kalasin to Pattaya the week before she was allegedly m𝑢rdєred, according to her family.

Witnesses say she encountered Mr Carman on a beachside street around 2am, after he had earlier been rejected by a woman at a bar, where he appeared drunk.

At 3:34am, CCTV captured him holding the teenager’s hand while entering his condominium building.

Police said he admitted to squeezing her neck until she lost consciousness.

About three hours after they entered his room together, Mr Carman was caught on camera walking out alone, wearing different clothes and carrying a small plastic bag.

Police allege Mr Carman had kept Ms Tunchanok’s body in his bathroom and went about his “normal life”, washing his clothes, and talking to neighbours.

After night fell, CCTV footage showed Mr Carman dragging a suitcase out of his room, which police allege contained the teenager’s body.

Police allege Mr Carman had packed the suitcase with all of the teenager’s belongings to clear his room of any evidence.

Officers were alerted the next day, and photos obtained by the ABC show one of the 17-year-old’s friends confronting Mr Carman in his room about the teenager’s whereabouts.

Mr Carman left for the airport later that day, where police eventually arrested him.

News of the 45-year-old’s arrest for murder has shaken those who knew him but who had not heard from him in years.

“I’ve got three girls. The oldest one is 17. I felt a bit sick in the stomach, to tell you the truth,” one family friend said.

“I just feel sorry for the family, and for everyone involved. It was a horrible thing to have happened.”