KEY POINTS:
The father of a teenage Kiwi boy who admits strangling their 51-year-old neighbour in Hawaii says his son is unremorseful - and does not understand the consequences of his crime.
Speaking to the Herald on Sunday from his Honolulu home, the father said he was disappointed that police
had not locked up the 15-year-old for his previous petty crimes - and that perhaps Karen Ertell's murder could have been prevented.
Ertell was found dead in her home across the street from the boy's Ewa Beach house last weekend. Police have described the killing as "outrageously heinous" in its planning, execution and cover-up attempts.
The father became suspicious when his son was arrested for stealing Ertell's car and released later that day, and called the police when the teenager told him he had killed her.
"I felt there was something he was hiding from me. He was scared. So I waited for my wife to come home, I asked him straight and he told me the truth."
Asked whether his son understood the seriousness of the crime, the father said "nope".
"He seems like it's nothing to him. He was trying to impress his friends," the father said.
The Herald on Sunday can also reveal that New Zealand police are helping their Honolulu counterparts to investigate the 15-year-old's past.
It is unclear if the teenager had a criminal record before leaving New Zealand four years ago, but it has been reported that he had been arrested more than 10 times in Hawaii on charges such as felony burglary, misdemeanour trespassing and misdemeanour theft.
Police spokesman Jon Neilson confirmed that New Zealand police had sent records to Hawaii but declined to discuss their contents.
The family moved to Hawaii four years ago after living on Auckland's North Shore for five years. The father said his son was well-behaved at home but had joined a local street gang. Warning the police that his son was robbing neighbours' homes, the father was told there was little the authorities could do because of the boy's age.
"I told police a long time ago that I was worried my son was stealing from houses, and I was worried he was going to be shot by someone, that he was going to die," he said.
Hawaiian prosecutors are seeking to try the 15-year-old as an adult for the murder of Ertell as well as possible charges of robbery, burglary and car theft.
Under Honolulu law, he would serve only four years if convicted as a juvenile. The adult age of culpability in the state is 18.
Police say there was no forced entry into Ertell's house or signs of a struggle, but police found blood inside and discovered her blue Volvo was missing.
Police initially arrested the New Zealand boy that day on suspicion of driving without a licence, then released him.
The next day, detectives arrested the boy at his home on a charge of second-degree murder after his father contacted them.