For the next seven hours he held her hostage in a residence's garage north of Brisbane, sparking an emergency declaration and street closures.
Standing behind the terrified woman, Hettrick told police he would kill her with the Bowie knife if they came close before ordering them to shoot him during the siege.
"He whispered to ... (the woman) he is sorry but it is his time to go and she is going with him," crown prosecutor James Bishop told the District Court on Wednesday.
When a "severely" drug-affected Hettrick finally released the woman from the Everton Hills home it ended a three-month crime spree.
Hettrick committed more than 30 offences from March 2020 including breaking into houses and cars, taking property and vehicles and using stolen bank cards, the court heard.
The 44-year-old father of two was on parole and had a suspended driver's licence at the time.
By May 2020 Hettrick was spotted by police in a stolen ute with the woman but sped away, abandoning the vehicle at Everton Hills.
The duo fled on foot, entering the garage before Hettrick began accusing the woman of "working with police to have him arrested", Mr Bishop said.
When officers approached the residence with a police dog, Hettrick "produced a large Bowie knife" and grabbed the woman, sparking the siege at 4am, the court heard.
"It must have been a horrendous experience for her," Judge Katherine McGinness said.
During the standoff with police, Hettrick caused about $12,000 worth of damage while barricading himself in the garage.
"Your offending was out of control, particularly at the end, and fuelled by drug use and addiction, escalating to a potentially life-threatening situation," Judge McGinness said.
Addicted to amphetamines since 16, Hettrick's "appalling" criminal history began in 1998 and includes a total of 22 previous sentences of up to six years in jail, the court heard.
Hettrick - who had been in custody since his arrest more than two years ago - pleaded guilty to a total of 34 charges on Wednesday.
He was sentenced to six years in jail but is eligible for parole from Wednesday, with his 752 days spent in custody considered time served.
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