An Indigenous teenager had been self-harming in the week before he attempted to take his own life in a storeroom at a privately run Perth prison.

Noongar and Wirlomin man Stanley Inman, 19, died in hospital two days after he was found in a critical condition at Serco-run Acacia Prison on July 11, 2020.

An inquest on Tuesday heard his mental health had been deteriorating in the week before his death.

Counsel assisting Jon Tiller told the court Mr Inman had been struggling with the deaths of two family members and his failing relationship with his girlfriend.

Corrections recordings of his phone calls revealed he had repeatedly talked about self-harm and suicide to his mother and partner.

During one call he said: “I can’t talk to anyone, I’ve got no psych”.

The day before Mr Inman was found by an officer in a critical condition, he attempted to call his girlfriend 14 times without success.

On July 11 he tried to call her a further four times and again she didn’t answer, likely because she had been taken into custody at a women’s prison, Mr Tiller said.

CCTV footage showed Mr Inman walking around with a laundry basket near the storeroom where he was found.

Correctional officer Micholas Manifis found the teen during an urgent search after he failed to attend the midday prisoner count.

“I looked straight at the storeroom and I knew something was wrong,” he said.

Mr Manifis said he tried to help Mr Inman but he was not breathing and he called for help.

“Code red, code red, prisoner (emergency),” he told Coroner Michael Jenkin.

Mr Manifis performed chest compressions on Mr Inman in the absence of a mask for mouth-to-mouth resuscitation before prison medical staff arrived with oxygen and a defibrillator.

Paramedics later took the teen to St John of God Hospital Midland in Perth’s eastern suburbs, where he was placed in an intensive care ward.

He was declared “life extinct” two days later.

Mr Tiller said the inquest’s primary consideration is the quality of supervision, treatment and care Mr Inman received at the prison.

“While Stanley did not have an explicit mental health diagnosis, it is apparent from the evidence that Stanley was experiencing acute mental emotional distress,” he said.

“It’s also apparent from the evidence that there was a disconnect between what Stanley told his family about his mental health and what he told health professionals.”

The coroner heard that on July 8 Mr Inman called his partner eight times and made repeated references to self-harm and suicide.

He also told correctional staff he wanted to kill himself and showed them fresh self-inflicted injuries to his chest.

As a result, he was placed on a high risk rating with one hourly observations and sent to the medical centre for assessment.

Mr Manifis said Mr Inman became emotional as they walked to the centre and said he wasn’t coping well.

But his demeanour abruptly changed once they arrived and “his emotions switched off”, the coroner was told.

He was placed in an observation cell and no further issues were observed during welfare checks.

The following day, Mr Inman met with staff at the prison’s psychological wellbeing services unit, who noted he was polite, engaged and didn’t show any signs of distress.

Mr Tiller said Mr Inman attributed his self-harm to increasing stress, and his grandmother and brother’s deaths.

He also said the teenager denied thoughts or plans to self-harm or suicidal ideation and was assessed a not being in a suicidal crisis before his risk rating was lowered to medium.

On July 10 a follow-up assessment found Mr Inman was flat and emotionless but responsive.

“He was maintaining appropriate eye contact and (again) denied self-harm or suicide ideation,” Mr Tiller said.

It was recommended his risk rating be decreased from medium to low, with four hourly welfare checks.

The inquest continues.