The killer of New Zealand-born nurse Michelle Beets appeared as if he "didn't really care'' when handed a life sentence in a Sydney courtroom today, says her brother.

Former marine Walter Ciaran Marsh, 51, will spend the rest of his life in prison for murdering his former boss on the doorstep of her Sydney home on April 27, 2010.

Marsh was convicted last November of using a military technique in a revenge killing when he slashed Ms Beet's throat and repeatedly stabbed her in the chest.

He had worked with Ms Beets at Sydney's Royal North Shore Hospital until his contract was not renewed in early 2010.


Marsh failed to find another job and believed his former boss was giving him bad references.

Without a job, he could have been forced to return to his native America, where he would have faced an unpaid US$50,000 (NZ$61470) child support bill for the maintenance of his teenage daughter.

Samantha Marsh, who gave evidence against her husband during a six-and-a-half week trial, told the jury that when he met her after the killing he said: "I did it, that bitch is gone.''

Ms Beets' brother Marty flew from Auckland to Sydney with his wife Leona to hear the sentence delivered and said it was hard hearing how his sister was killed.

"It was horrifying to listen to the detail of the actual wounds to Michelle, and horrifying to listen to the plans that were involved in him leading up to murdering her. I'm still a bit numb, and it only really felt like yesterday but 18 months has passed.''

Mr Beets heard how Marsh had planned his sister's murder, by scoping out her home, planning a getaway, and practicing throat slitting and stabbing motions using a wooden spoon.

"It was a cold, calculated crime,'' he said.

During today's court appearance, Marsh appeared to show no remorse "whatsoever'', said Mr Beets.

"He basically seemed to be in a world of his own. He didn't look around that much, he seemed to be looking at a piece of paper and writing notes. He didn't really care.

"I'm not really too sure what to feel. It feels like closure but it's not. It's like we're still too numb at the moment.''

Asked if he thought Marsh deserved the life sentence, he replied: "I believe so.''

Mr Beets, who was waiting to inform his Queensland-based father of the sentence, said the hearing represented some kind of closure but he didn't know how he felt about his sister's killer.

"You think, 'you know what, if I could put a gun on him now' ... I don't really know, he's just another human being who made a mistake, a very, very serious mistake.

"The malice part, I'm not really too sure. Would I help him go and change a tyre? I don't know.

"I think it's partly because I'm removed from it, I'm numb at the moment.''