A man in Heilongjiang province was sentenced to death and his wife to life in prison on Monday for murder, rape and robbery in the death of a teenager who had been lured into their home.

Bai Yunjiang and his wife Tan Beibei murdered 16-year-old Hu Yixuan after Bai failed in his attempt to rape her on July 24, 2013, according to the province's Jiamusi Intermediate People's Court.

On that day, a pregnant Tan pretended she had belly pains and asked Hu, who was walking by, to escort her home, the court said, in order to lure the girl into the couple's home.

At the couple's home, Bai gave Hu yogurt that was poisoned with a drug to make her unconscious. But the court said he failed to rape her after she fell asleep. The couple then suffocated the girl, put her body in a suitcase and buried it.

The couple was arrested on July 28 and the body was identified the next day.

Before the murder of Hu, Bai had raped two other girls last year, the court said. In both of these cases, Tan lured them into the couple's home and gave them sedatives, after which the couple robbed them of their jewelry and Bai raped them, according to the court.

The convicts pled guilty and apologized to Hu's family during a court hearing last week.

In the judgment, the court said that the couple deserved such extreme punishments, as their motives were despicable, the murder was brutal and the case brought great negative influence.

Because Tan was pregnant during her detention and court hearing, the court did not give her the death penalty under the current Chinese Criminal Law.

The convicts were also asked to pay 374,499 yuan ($60,840) to Hu's family.

Bai said he will appeal to a higher court, while Tan accepted the punishment.

Sun Hongbo, Hu's mother, was absent when the judgment was announced. The 43-year-old mother said on Monday that she was afraid to hear the case in court and that she could not accept Tan's life sentence.

The Jiamusi government is providing Sun with basic living allowances and a job, which can bring up to 1,200 yuan monthly, because her family lost their only child.

"I'm poor and old, so I don't want to have another kid," said Sun, who added that she will speak with her lawyer about whether the compensation is reasonable.

Wu Ming'an, a criminal law professor at the China University of Political Science and Law, approved the court's verdict, saying a woman cannot be sentenced to death if she is pregnant.

"So the judgment is reasonable, although the woman's behavior was harsh," he said.

Bao Yunhe, the mother of a 2-year-old girl in Jiamusi, said she has followed the case. She said Tan did not respect life, including her unborn baby, at that time.

"I'll tell my kid to take her own safety as priority, even though helping strangers should be encouraged," she added.

The convicted couple married in 2012, but fell out of love in May 2013 when Bai found out Tan had extramarital affairs with other men. The court said Tan felt sorry for her affairs and started luring girls home to Bai, the statement added.

Tan gave birth to a boy on Aug 6, 2013. No one from Tan or Bai's families will take care of the baby, but police said they have received phone calls from across China with offers to adopt the child because "he is innocent".