Sick relationship that led to baby being cut from womb

Savanna Greywind, pictured, was murdered by Brooke Crews. Photo / News.com.au

An America woman convicted of killing her pregnant neighbour by hacking the baby from her womb has told a court she was under pressure from her boyfriend to "produce a baby" after he figured out she was faking a pregnancy.

It's been more than a year since the body of Savanna Lafontaine-Greywind, 22, was pulled from a North Dakota river, days after her healthy, days-old baby was found inside the apartment of convicted murderer Brooke Crews.

Crews pleaded guilty to killing the heavily pregnant Native American woman inside her Fargo apartment in August last year and was sentenced to life in prison without parole in February.

Months after Crews, 38, was jailed for life, her ex-partner William Hoehn is on trial for conspiracy to commit murder.

The convicted murderer said Hoehn appeared "surprised" when he walked into the bathroom of their apartment and found his then partner cleaning up Savanna's blood.

Hoehn told police Crews then bent down and picked up Savanna's baby, an infant girl and said: "This is our baby. This is our family."

Hoehn, 33, has previously admitted to helping his girlfriend cover up the murder but maintains he played no part in the brutal killing.

William Hoehn and Brooke Crews. Photo / Cass County Sheriff's Office / AP

But today, Crews told the court that when she verbally wondered if Savanna was dead, Hoehn grabbed a piece of rope and strangled the dying woman, telling Crews: "If she wasn't dead before, she is now."

Hoehn spoke regularly with his lawyer, Daniel Borgen, during Crews's testimony but showed little emotion. Crews was crying and sniffling throughout.

"You never told Will that you had planned to do this, is that right?" Mr Borgen asked.

"Not kill Savanna for her baby, no," Crews replied.

"In fact, there was never a conversation at all about killing Savanna and taking her baby," Mr Borgen said.

"Not explicitly," she responded.

Crews told the court her and Hoehn's relationship was fuelled by alcohol and drugs and was often violent.

The 38-year-old said she decided to pretend she was pregnant after they broke up and Hoehn had said he was going to end their relationship for good.

Crews then concocted the scheme, even emailing Hoehn a fake ultrasound photo and a picture of a positive pregnancy test.

But by early August, Hoehn had grown suspicion, telling Crews she needed to "produce a baby".

"I took that to mean I better have a baby, no matter how it happened," Crews told the court, describing Hoehn's suspicion as an "ultimatum".

Crews saw her opportunity to "produce a baby" on August 19 last year, when a heavily pregnant Savanna visited the apartment for a dress fitting.

Haisley Jo survived the murder of her mother. Photo / Facebook

In court this week, Crews stuck to her story, saying she pushed Savanna, who was knocked out when her head hit the bathroom sink and that's when she started using a knife to cut the baby out.

Forensics later determined she'd been subject to "homicidal violence" however, medical examiners are unable to say if she died from blood loss or strangulation.

Crews also told the court the couple kept ropes around the house because Hoehn liked to tie her up during sex, including around her neck.

She also said Hoehn expressed fantasies about killing people and Crews said she initially told him she would be interested in that too.

In December, the ex-husband of Crews told news.com.au she had been obsessed with serial killers for years.

Andrew Murray, a chef from Sydney's Blue Mountains, said he and Crews had hit it off online and she moved to Australia in February 2012.

"We ended up getting together and getting married," Mr Murray previously told news.com.au.

The couple were only married for a few months before Crews flew back to the United States in October 2012 but during their brief time together, Mr Murray said his wife had a dark side.

"As time passed on, she seemed to get more and more aggressive," Mr Murray said.

"She started getting nasty and saying the police wanted to speak to me so I walked in there and said, 'I understand you want to speak to me.' I gave them my licence (because) I had nothing to hide."

He said she was obsessed with true crime.

"She studied psychology and nursing and did her thesis on serial killers. She was always reading books on serial killers and murders and could tell you anything about them," he said.

Less than five years later, Crews went on to murder Savanna.

Immediately after she went missing, vigils were held around the state and a monumental search effort was launched.

Police searched the apartment three times with Crews today testifying that police missed Savanna's body and her baby.

Crews told the court Savanna's body was in the bathroom closet and the baby was covered up next to Hoehn on a bed during one of those searches.

Eventually, Crews claims, she and Hoehn put Savanna's body into a hollowed-out set of drawers and they carried it out of the apartment.

Haisley Jo, Savanna's infant baby, was found in Crews's apartment days after her mother was murdered.

She was miraculously in good health and returned to her remaining family.

Savanna's death prompted North Dakota Senator Heidi Heitkamp to introduce Savanna's Act, which aims to improve tribal access to federal crime information databases and create standardised protocols for responding to cases of missing and slain Native American women.