The case of Zhang Yingying, the missing Chinese scholar who was brutally killed in Illinois two years ago, came to an end on Thursday after the killer, Brendt Christensen, was sentenced to life in prison, without Yingying's body having been found or its whereabouts revealed.

Following the verdict, her parents expressed gratitude to the jury and people who have offered help and support throughout the case, and publicly appealed to Christensen to reveal where their daughter's body is so that the family can take her remains back to China.

"The jury has already made a decision, and the trial has ended. Yet Yingying still hasn't returned home," said Zhang's father in a statement. "Our goal has always been, and will always be, bringing Yingying home. Unless we do this, we will not find our peace."

"Although we disagree with this verdict, we can accept that the killer will spend the rest of his life behind bars, which will make up for us in some way. We hope that every day in prison, the killer could feel the pain we feel after losing Yingying."

"If you have any humanity left in your soul, please end our torment. Please let us bring Yingying home," Zhang's father appealed. As he spoke, Zhang's mother, Ye Lifeng, sobbed and seemed to be supported by the women standing next to her.

The U.S. Attorney for Central Illinois, John Milhiser, said that efforts to find Zhang's remains would continue. However, prosecutors have indicated in court filings that Christensen may have destroyed the remains.

The jury deliberated on the sentencing for more than eight hours over the course of the past two days. Reportedly deadlocked, they couldn't reach a unanimous verdict Thursday on whether to put Christensen in prison for life without parole or give him capital punishment, which automatically results in a life sentence. A death sentence requires the unanimous agreement of all jurors.

On Friday, Chinese Foreign Ministry expressed strong indignation and condemnation of the cruel acts of the murderer.

The Chinese government attaches great importance to safeguarding the security and legitimate rights and interests of Chinese citizens overseas, said Geng Shuang, a spokesperson from the ministry.

The government will continue to follow up on the progress of the case and to help Zhang’s family in handling affairs in the United States, Geng added.

Testimony phase

During the poignant testimony during the penalty and sentencing phases, Zhang's parents told jurors how the family was devastated by the loss of their beloved daughter, who had aspired to become a professor when she came back China and that Christensen dashed Zhang’s dreams and those of her family.

"How am I supposed to carry on living? I really don't know how to carry on,” Zhang's grief-stricken mother said in testimony by video.

Yingying was killed months before she had planned to get married.

"I wanted to see her in a wedding dress," said Zhang's mother Ye Lifeng, adding that she was looking forward to her daughter's wedding in October 2017. "My daughter did not get to wear a wedding dress. I really wanted to be a grandma."

Zhang's father also told jurors Yingying is part of his life: "Without her, my life will not be complete."

On the side of Christensen, the defense sought to humanize Christensen by showing home videos of him playing the piano and opening Christmas gifts as a child.

The attorneys asked the 12-person jury to show mercy and spare Christensen, applying for Christensen's parents, friends and relatives to testify for him in the penalty phase. All the witnesses presented a bright side to Christensen.

Christensen’s sister, Andrea Christensen, told jurors that her brother had been her role model and that he was never aggressive to anyone when they were growing up. And Christensen's uncle described him as a "happy go-lucky kid... just a real nice kid."

The defense attorneys presented roughly 50 mitigating factors to the jury, ranged from his mother's alcoholism, his family's history of mental illness, depression during his childhood, his night terrors to his homicidal thoughts in the weeks and months before he killed Zhang.

The 26-year-old Chinese scholar went missing on June 9, 2017, after getting into a black Saturn Astra about five blocks away from where she got off a bus on her way to an apartment complex to sign a lease.

Prosecutor Eugene Miller said Christensen posed as an undercover officer and lured Zhang into his car when she was running late to sign an apartment lease. According to prosecutor, Christensen had approached a different woman earlier, posing as an officer, but that she refused to get in the car.

The muscular Christensen likely forced Zhang into a six-foot-long duffel bag that he bought online days earlier and carried her up to his apartment in Urbana, 225 kilometers southwest of Chicago. Once inside, he raped, choked, pummeled her with a baseball bat before decapitating her in 2017.

Christensen was arrested on June 30, 2017, after being caught on tape pointing out people he described as "ideal victims" during a vigil in Zhang's honor. 

The killer was convicted for kidnapping and killing of the visiting scholar on June 24, and the penalty phase began on July 8 before Christensen was sentenced on Thursday to life imprisonment without possibility of release.

Judge James Shadid announced the verdict in a federal court of Peoria in the U.S. state of Illinois.

June 9, 2017: Visiting scholar Yingying Zhang is reported missing.

June 30, 2017: Christensen is arrested on kidnapping charges.

July 12, 2017: A federal grand jury indicts Christensen.

July 20, 2017: Christensen pleads "not guilty" to one count of federal kidnapping.

Oct. 3, 2017: A federal grand jury returns a superseding indictment charging Christensen with one count of kidnapping resulting in death and two counts of making false statements to the FBI.

Oct. 11, 2017: Christensen appears in court and pleads not guilty to the three charges.

Feb. 27, 2018: Christensen's trial is set to begin.

June 3, 2019: Guilt phase of trial begins.

June 24, 2019: A federal jury finds Christensen guilty of kidnapping and murdering Zhang Yingying.

July 8, 2019: Penalty phase of trial begins.

July 19, 2019: Brendt Christensen is sentenced to life in prison without parole.

(With input from agencies)