Defence lawyers had argued Montgomery was mentally ill

After four hours of deliberation, they rejected Lisa Montgomery's plea that she had been delusional when she killed Bobbie Jo Stinnett and stole the baby.

Prosecutors are seeking the death penalty for Montgomery, convicted of kidnapping resulting in death.

The baby, a girl, survived and was later returned to her father.

'Voodoo science'

Montgomery met the Stinnetts at a rat terrier dog show in Kansas in April 2004.

Having learnt of Bobbie Jo's pregnancy, in December 2004 she used a fake online profile to set up a meeting at the Stinnett family home saying that she wanted to buy a terrier puppy.

Victoria Jo Stinnett is now nearly three years old

A doctor testifying in the trial said that Bobbi Jo was probably still alive when Montgomery started removing her child.

Montgomery's lawyers had sought to portray their client as a victim of severe mental illness whose delusion of being pregnant - pseudocyesis - was being threatened, causing her to enter a dreamlike state when the killing took place.

They also argued that she had post-traumatic stress disorder brought on by mental, physical and sexual abuse in her childhood.

Federal prosecutor Roseann Ketchmark called the claim of pseudocyesis "voodoo science".

Healthy child

Instead, the prosecutor argued that Montgomery had feared her ex-husband, Carl Boman, would expose that she was lying about being pregnant and use it against her as he sought custody of two of the couple's four children.

"It's not pseudocyesis or post-traumatic stress disorder," Ms Ketchmark said in closing arguments.

Mrs Stinnett thought her visitor was coming to buy a puppy

"And even if you wrap them up and put delusions around them, it's not insanity."

Mrs Stinnett, 23 and eight months pregnant when she was killed, fought for her life and that of her child, the trial heard.

Nodaway County Sheriff Ben Espey, who was the first law enforcement officer to arrive at the Stinnetts' home in Skidmore, Missouri, said in his testimony:

"You could see swirls in the floor in the blood, showing there was a struggle."

Her killer was arrested the day after the crime having spent the morning showing off the infant as her own in her hometown of Melvern, Kansas.

"The only good thing that comes from this tragedy is that little Victoria is a healthy baby and is reunited with her family," US Attorney John F Wood said.