When a young mother disappears in Columbia, Missouri, investigators use DNA from a tree to help solve the mystery of what happened to her
December 2014: Mengqi earns her master's degree
After emigrating from China to further her education, Mengqi Ji earned a master's degree in mechanical and aerospace engineering from the University of Missouri. At the time, her future husband Joe Elledge was also studying engineering there.
Sept 8, 2017: Joe Elledge and Mengqi Ji's whirlwind romance
Mengqi Ji and Joe Elledge met in September 2015. They both worked as engineers at a company named Nanova. Mengqi was Joe's supervisor. Their first date was in January 2016. Joe proposed on Sept. 8, 2017, while on a hike in Rockbridge Memorial State Park.
Sept. 22, 2017: Joe and Mengqi get married
After a short engagement, Joe and Mengqi were married on Sept. 22, 2017.
February 2018: Mengqi learns she is pregnant
After finding out she was pregnant, Mengqi was overjoyed, but shortly after their daughter was born, trouble began to brew. The couple found themselves constantly arguing.
Mengqi's parents, pictured with their daughter, traveled from China to help care for their granddaughter, but their presence only increased tension between Joe and Mengqi.
Oct. 9, 2019: Mengqi disappears
Joe says that on the night of October 8, he approached Mengqi to give her a massage and initiate intimacy. However, according to Joe, Mengqi rebuffed his advances and, claiming she had plans the next day, she went to bed around 11 p.m. Joe says when he woke up in the morning, she was gone, leaving behind her car keys, cell phone, wallet and, most importantly, the couple's 1-year-old daughter.
Oct.10, 2019: A mother's instinct
Mengqi spoke with her mother in China every day, so when she missed a day, her mother became concerned and sent a friend to check on her. That's when Joe admitted his wife was missing and finally reported her disappearance to police.
However, Joe did not call 911. He called the non-emergency 311. This is police bodycam footage of a visit to their home.
Oct. 15, 2019: A husband's plea
Joe Elledge gave an interview to CBS affiliate KRCG. He said he needed his wife to return home safely, and that he and his daughter loved her. He also implied that Mengqi may have run off with another man, stating, "I hope that she's, at least with somebody who cares for her, you know, enough to keep her safe."
Oct. 15, 2019: Joe's police interview
That same day, Joe also voluntarily sat down for an extensive interview with the Columbia Police Department. Investigators soon became suspicious of his story, especially after Joe described going for long, leisurely drives to look for new hiking paths instead of searching for his missing wife.
Oct. 15, 2019: Police discover secret recordings
The same day Joe was interviewed at the police station, investigators asked to see his cellphone. On it, they discovered 10 hours of secretly recorded arguments between Joe and Mengqi. Both Joe and Mengqi's cellphones are pictured here.
Joe got defensive in some of these recordings. In one recording he said, "What are you trying to do? Are you — seriously? Are you trying to, like, get the baby away? Are you trying to make me go crazy so that you can call the police on me and take my (expletive) baby away from me?"
A broken marriage revealed
Later, officers were able to recover nearly four-and-a-half additional hours of recordings from Mengqi's phone. A transcript of one of those recordings can be seen here.
"What was on those conversations of significance?" Peter Van Sant asked then-prosecutor Dan Knight. "Unvarnished Joe Elledge," he replied.
In those recordings Joe told Mengqi, "You think you're so empowered because of this society. Well, don't forget that nature exists. You're still just a woman."
Oct. 25, 2019: Joe Elledge arrested
The Columbia Police Department announced that they were opening a criminal investigation into Mengqi's disappearance.
The same day, officers arrested Joe Elledge, but not in connection to his wife's disappearance. Instead, he was arrested on suspicion of physical child abuse. Officers had learned about some bruises on his daughter. Joe admitted that he pinched the baby one day when she was crying. His bail was set at $500,000.
Oct. 29, 2019: Searching the Lamine
After analyzing cell tower data, investigators discovered that on the day he says his wife disappeared, Joe visited the Lamine River, about 40 minutes away from the couples' home.
Joe hadn't mentioned this to police, so officers became suspicious that perhaps the river had to do with her disappearance.
Highway Patrol did a surface search at the Lamine River, hoping to find clues. It was the first of many searches there, which included dive teams and cadaver dogs, but nothing was ever found.
Oct. 30, 2019: Custody case begins
Joe Elledge's mother filed for guardianship of his young daughter. Just days later, Mengqi's parents filed for guardianship of their granddaughter. Mengqi's mother and daughter are pictured.
Ultimately, the baby would live with Joe's mother while the custody case was resolved.
To this day, their custody dispute is ongoing with no resolution, in part due to delays caused by COVID-19. A decision in the custody case is expected by the end of December 2022.
Feb. 19, 2020: Joe Elledge is accused of murder
Despite not being able to locate Mengqi, then-Boone County Prosecutor Dan Knight decided to file first-degree murder charges against Joe Elledge for the death of his wife. After reviewing the audio recordings found on Mengqi's phone, Knight became convinced that Joe had something to do with his wife's disappearance. Knight and his team began preparing for trial.
Feb. 22, 2020: A memorial for Mengqi
After months of searching for Mengqi, authorities still couldn't find her. Mengqi's mother attended a memorial vigil in her honor at the Lamine River.
March 25, 2021: Mengqi Is found
Seventeen months after Mengqi's disappearance, a hiker stumbled upon her skeletal remains, in Rock Bridge Memorial State Park -- the same park where Joe had proposed to her. A memorial for Mengqi is pictured.
Broken ribs
Mengqi was found with four broken ribs, an injury that Prosecutor Dan Knight believes shows that she was killed in a violent confrontation
August 2021: The power of plant DNA
At the time of Joe's arrest, officers had collected muddy boots from Joe and Mengqi's apartment. Plant population geneticist Christine Edwards, and her team at the Missouri Botanical Garden, were asked to compare plant DNA recovered from those muddy boots to plant samples recovered from trees near where Mengqi's remains were found.
The tree that helped solve a murder
The prosecution said DNA from the tree hanging over Mengqi's burial site matched samples from the boots, ultimately linking Joe to that exact location. Christine Edwards told Peter Van Sant, "Once we found the match, I became very convinced that he buried his wife."
Alex Linan, pictured here with correspondent Peter Van Sant, is an assistant scientist at the Missouri Botanical Gardens.
Nov. 2, 2021: A new story
Faced with the fact that Joe Elledge was now placed at the scene of Mengqi's burial site, Joe's defense attorney Scott Rosenblum presented a new story at trial. He argued that Joe did in fact kill his wife, but it was a tragic accident.
Rosenblum said the couple got into an argument and began shoving one another. He claimed when Joe shoved his wife, she fell backward, and Joe heard a thud. After she told him to leave her alone, Joe claims he went for a walk and Mengqi went to bed.
The next morning, Rosenblum said Joe awoke at 5 a.m., heard his baby crying and found his wife dead. "He was in a dissociated state of denial," said Rosenblum. Panicking, the attorney said, Joe decided not to call 911, and later buried his wife. "Once he went down that rabbit hole, he chose to continue down that path," he said about his client's lies to Columbia police.
Establishing a Motive
After opening statements, Prosecutor Dan Knight played those secret audio recordings between Joe and Mengqi showing them arguing, including Joe telling Mengqi she was "brainless." Knight told Peter Van Sant that the recordings helped establish motive. "It was a calculated effort on his part … to bring her under his control," he said. Knight believes that when Joe couldn't control Mengqi, he decided he wanted her gone.
Nov. 9-10, 2021: Joe Elledge testifies
Joe Elledge spent two days on the witness stand. Dan Knight questioned Joe for nearly three hours to pinpoint a cause of death.
Knight asked, "You killed Mengqi on that bed, didn't you?" "No," Joe replied. Knight also asked if he stood on top of her back and jumped on her or suffocated her. Joe replied no to those questions.
Joe reiterated that Mengqi's death was an accident.
Nov. 11, 2021: A guilty man
After a 10-day trial, both sides delivered closing arguments. Defense attorney Scott Rosenblum reiterated that it was all a tragic accident and argued for manslaughter. Dan Knight argued that Mengqi's death was premediated and asked for first-degree murder.
Neither side got what they wanted. The jury found Joe Elledge guilty of second-degree murder, meaning that they didn't see Mengqi's murder as premediated. The jury then recommended a sentence of 28 years in prison. Prosecutor Dan Knight believes the sentence may signify a year of prison time for each year of Mengqi's life.
A sudden loss
On June 4, 2022, Dan Knight who worked so hard to get justice for Mengqi, died unexpectedly.
Remembering Mengqi
Mengqi's friends and family remember her as artistic, smart and kind, and say she will be missed deeply by all who knew her. In her short 28 years of life, she was a bright light with a kind soul and a love for her Chinese culture and her family.
