A Circuit Court jury took less than three hours to decide that convicted killer Glenn Keohokapu Jr. is so dangerous to the public that he can be locked away in prison for life.

Keohokapu, 36, was convicted last month of manslaughter in the June 2008 stabbing death of 19-year-old Steven Wilcox outside a Kane'ohe karaoke club.

Prosecutors had charged him with second-degree murder — punishable by life in prison with the possibility of parole. But jurors convicted him of the lesser offense, which carries a maximum punishment of 20 years behind bars.

Prosecutor Peter Carlisle's office then invoked a law passed by the Legislature in 2007 that allows a jury to impose longer sentences for "persistent offenders" who pose a danger to the public.

It's just the second time the law has been invoked since its passage.

The panel began deliberating shortly after 11 a.m. and by 2 p.m. had reached its decision.

Circuit Judge Virginia Crandall is not required to sentence Keohokapu to the extended term of life with the possibility of parole. She will impose a sentence in a hearing June 22.

Defense lawyer Benjamin Ignacio said after the verdict was returned that he was "disappointed" by the decision and planned to argue for a 20-year sentence from Crandall.

Deputy Prosecutor Kristine Yoo said, "We are very pleased with the jury's decision."

She called Keohokapu "a danger to the community" who deserves "a life sentence with the possibility of parole."

During yesterday's hearing, Ignacio told the jury that Keohokapu "is not a remorseless individual," or the "kind of offender who goes out in search of trouble, who visits random violence on society."

The 20-year term for manslaughter "is what the law has decided is appropriate for this type of offense," Ignacio said.

Most of Keohokapu's past convictions — for burglary, robbery, promotion of detrimental drugs and domestic violence — were related to his stormy relationship with his wife, Kauilani, said the defense lawyer.

"Glenn has a blind spot for Kaui," Ignacio said. "She places a lot of stress on him."

Yoo called Keohokapu a man whose history of violence has escalated over the years.

"When he's angry, he gets violent and cannot control himself," she said.

That violence finally "escalated into the death of another person," she said.

Keohokapu and his wife have "a dysfunctional relationship," the prosecutor acknowledged. "Does that mean other people have to suffer because of their dysfunctional relationship?"

During the sentencing hearing, Keohokapu's father testified that he had been "a terrible father" who repeatedly beat and even bit his young son without provocation over a period of years, Ignacio pointed out.

"Glenn Junior never had a fair chance in life," Ignacio said.

Yoo responded to that argument by saying, "What chance did Steven (Wilcox) have in life?"

Wilcox was fatally stabbed in the heart after he tried to intercede in an argument between the Keohokapus the night of June 8, 2008.