Inside the Isolated Rockingham Background of Accused Thai Suitcase Killer Simon Carman

Exclusive: A former associate of the Perth mechanic accused of killing a Thai teenager reveals his severe physical limitations and heavy use of prescription opioids.

By Wade McColl (29/06/2026)

Suspected suitcase killer Simon Peter Carman, suitcase containing the body of the 17 year-old victim, Simon Peter Carman brandishing a shotgun in his home. Photos: supplied.

The Rockingham man facing the death penalty in Thailand for the brutal murder of a teenage girl lived a highly medicated, isolated existence in Western Australia’s southern suburbs, a lifestyle that stands in stark contrast to the brutal physical nature of the crimes alleged by international authorities.

Simon Peter Carman, 46, was intercepted by Thai immigration authorities at Suvarnabhumi Airport on Friday night, moments before he was scheduled to board a Jetstar flight back to Perth. His sudden arrest followed the grim discovery of 17-year-old Tunchanok Donhomla, whose naked body was found packed inside a 29-inch black suitcase left in a grassy area near a Pattaya railway line.

Surveillance footage captured Carman leading the teenager into his $100-a-week Jomtien Condominium apartment at 3:30 AM on Thursday. Further CCTV clips allegedly show him hours later, dragging a large, heavy suitcase out of the building and strapping it onto the back of a motorbike

Suspected suitcase killer Simon Peter Carman in custody, and the apartment where Carman reportedly lived in Pattaya. Photos: Pattaya News.

While international media outlets have focused heavily on his transient lifestyle in Pattaya's red-light districts, a local associate who lived near Carman during his time in WA spoke exclusively to the Baldivis Times to provide critical context regarding the accused man's deteriorating health.

Heavy Medication and Severe Spinal Injuries

Speaking on the condition of total anonymity, the long-time ex-contact revealed that Carman suffered from debilitating spinal injuries caused by a severe past accident during his career as a truck driver.

"He broke his back truck driving and got a big payout," the source told the Baldivis Times. "He was on a lot of painkillers, like ketamine, nerve blockers, and all that kind of stuff. All sorts of real hardcore stuff."

The associate alleged that the massive cocktail of severe prescription drugs left Carman permanently slowed down, altering his physical gait and speech so severely that it eventually gave away his identity on international television news broadcasts.

"I wasn't sure whether it was him at first or not, and then I saw his walk and I was like, 'oh, yeah, that's him,'" the source alleged. "He was just really slow all the time, the way he talked, the way he moved, everything about him. Spaced out with a certain cadence."

These claims directly align with independent local reports stating Carman had metal pins in his spine and neck from a motor vehicle accident in his 20s, and had travelled to Thailand specifically seeking an operation to remove them because Australian doctors refused to perform the procedure.

Suspected suitcase killer Simon Peter Carman pictured holding a shotgun in his home. Photo: supplied.

'Simple Simon' Lived an Isolated Life in Rockingham

According to local records, Carman spent roughly a decade, leading up to his departure for Thailand, living on and off inside an industrial estate unit in Rockingham, where he reportedly survived on a combination of a disability pension and workers' compensation payments.

"He just stuck to himself really," the source recalled, stating that Carman was a "real simple man" who spent years living in isolation, occasionally sharing drinks with neighbors but rarely opening up. "He'd stick around and have a few beers with us, but he'd never get past loose. He had a dark sense of humor, it was quite funny."

When asked about the shocking charges emerging from Thailand, the former associate expressed profound shock, noting the massive disconnect between the slow-moving neighbour they knew and the grim footage captured on Pattaya surveillance cameras.

"What he's done, I'm shocked. I'm really confused," the source told the Baldivis Times. "He wasn't quick, he wasn't fit. You wouldn't think he'd even be capable of it, to be honest with you. He didn't portray himself in that sort of manner."

Confiscated Weapons and an Interrogation Room Confession

Despite descriptions of a slow-moving demeanour, Carman’s history in the Rockingham region contains alarming red flags. Neighbours within his industrial complex previously reported that WA Police had confiscated a collection of firearms from Carman, including a shotgun and a .22 calibre Hornet rifle, roughly a year before he left for Southeast Asia due to growing concerns surrounding his mental stability and improper gun storage.

CCTV footage capturing Tunchanok and Carman entering his accommodation, and the suitcase, which was discovered approximately 4.2 kilometres from Carman’s accommodation. Photo: Pattaya News.

In a Thai interrogation room, Carman denied intentional murder, telling police that he acted entirely in self-defence after a heated argument over the cost of sexual services escalated and the 17-year-old girl allegedly attacked him with a knife.

When pressed by investigators about deep fingernail scratches covering his arms and neck, Carman dismissed the injuries on camera, claiming:

"I think it's a spider; they always get in here."

In video footage recorded by Pattaya City Police, Carman addressed the victim's family directly.

"I feel bad for what happened to your daughter. It was out of my control," Carman said. "I know you'll be very sad, upset, same as me. Please tell other girls just to be careful."

The victim’s stepmother, Oradee Bussarakum, has publicly rejected the apology and demanded that Thai authorities execute the 46-year-old mechanic.

"I told the police I want him executed," she said

Carman remains in strict custody in Thailand as international investigations proceed.