HOUSTON, Texas -- A Texas man who has spent more than five months in a Russian detention center is facing a different challenge from other recent American detainees such as Trevor Reed and Brittney Griner, as authorities in Moscow are accusing him of wrongdoing in his home country, ABC News reports.
David Barnes, a Huntsville, Alabama, native who has lived in the Houston area in recent years, was taken into custody by law enforcement in Moscow in January and has been incarcerated on Russian soil ever since.
"If I could go over there and just sit in that place with him, I would do it in a minute, because this is the most unjust situation I've ever experienced in my entire life," Carol Barnes, David's older sister, told ABC News. "I feel like part of me is missing."
David was in Russia attempting to gain legal clearance to either see his children or bring them home, after his Russian ex-wife allegedly violated a court custody order and fled the United States with them, his family told ABC News.
On Jan. 13, Russian investigators apprehended David in Moscow, accusing him of abusing his two children years earlier in Texas, according to translations of court documents. Similar allegations against David were brought to authorities in Texas by his now-ex-wife Svetlana Koptyaeva during their long and acrimonious divorce proceedings. The allegations were investigated in 2018 by the Department of Family and Protective Services, which found insufficient evidence to support them and closed the case without any findings of abuse or any charges against Barnes.
David's ex-wife is also now wanted in the U.S. on a felony charge of interference with child custody, after she fled with the children in 2019.
"His mission was to save his children," Carol said. "His mission all along has not been really revenge against her at all."
With her brother locked up abroad in a country that is currently fighting a war in Ukraine that has led to a diplomatic dispute with the United States, Carol said she worries about his future.
"I've never been so sad and so hurt," she said. "All I think about is the conditions that he's living in."
Making 'examples out of U.S. citizens'
For much of his time in Russia, Barnes has been in Moscow's Detention Center 5, according to his family. He is not the only American, or even the only Texan, who has been held there in recent years.
Trevor Reed, a former Marine from Texas, was arrested by Russian authorities in 2019 and sentenced to nine years in prison. After being accused of assaulting two police officers in Moscow, Reed spent part of his time behind bars in Detention Center 5.
After Reed's case gained widespread publicity in the U.S., he was released by Russian authorities in April in exchange for a Russian man who was being held in Connecticut on a federal drug trafficking conviction.
WATCH: 'I fought': Trevor Reed describes his survival in a Russian prison
In an interview with ABC News, Reed described his pretrial Russian detention facility as rat-infested and "extremely dirty."
"It took Trevor Reed three years to get out and his alleged crime was much less severe than what David is being accused of," Carol said. "We're talking about Russia. They're going to make examples out of U.S. citizens."
Another Texan, Brittney Griner, is still being held by Russian law enforcement in the Moscow area. The WNBA star and Olympic gold medalist was arrested at an airport after Russian authorities alleged that she had vape cartridges with hashish oil in her luggage, but the U.S. government says Griner is being "wrongfully detained."
SEE RELATED STORY: WNBA star Brittney Griner trial starts in Russia court
David had been living in Texas since 2007, working initially as a design engineer for an Alabama-based software company's Houston office.
Houston is where he met Koptyaeva, who was also living there for work. The two married and now have two sons, at least one of whom has dual Russian and American citizenship.
"I saw a difference in him when he had those two children," Carol said. "His boys were his only focus in this life."
Koptyaeva filed a petition for divorce in 2014, and over the next five years, a lengthy and ugly custody battle ensued between the two parents, resulting in a jury trial and numerous court hearings in Texas.
"It was horrible," David's younger sister Margaret Aaron said. "She tried everything she could to take the children from him and to get sole control, and he fought her tooth and nail."
Of David's two children, Carol said, "He wanted them, even though their parents were divorcing, to have two parents. He thought that children should be raised by two parents' influence."
Paul Carter, a lifelong friend of David who is also divorced with two sons, said the struggle between David and his ex-wife became "a cascading series of events" stemming from "her desire to not have David in any part of their lives."
"My boys are everything," Carter said. "Watching my sons grow up has been a wonderful experience. I've wanted so much for David to have that."
'Completely and totally devastated'
In early 2019, as part of a custody arrangement, Koptyaeva was expected to bring the children to an agreed-upon meeting point so David could have the boys for a few days.
However, she never showed with the children. According to law enforcement records, David called the Montgomery County Sheriff's Office multiple times to ask for welfare checks on the two boys.
"She was a flight risk and somehow was able to flee with the passports," Carter said. "I think that's a real travesty. It's a real breakdown of the system."
By April 6, 2019, the FBI was able to track Koptyaeva to Turkey, according to a criminal complaint.
"He was completely and totally devastated," Aaron said. "He had gotten their room ready at his apartment and bought them toys, and he was just so happy that they were going to come back to him, and then they were gone. He was crushed."
In August 2020, a judge in Montgomery County signed an order designating David as the sole managing conservator of his children, which gave him rights to decide the primary home for his children, make decisions regarding their education, represent them in legal actions, and possess their passports.
Yet despite the order, the two boys were nowhere to be found in the U.S. and David was unable to reestablish contact with them.
His family said he had a gut feeling about where the children had ended up.
"He was pretty certain what had happened, that [Svetlana] had taken them back to Russia," Aaron said. "He knew that she would probably do this if she had the opportunity."
Koptyaeva was eventually traced to her homeland, with court-appointed receiver Robert Berleth writing in a November 2020 report, "It is understood by the Receiver the Defendant has fled to Russia and has no intention of returning" to her home in Texas.
Carol said that after locating and hiring an attorney in Moscow, her brother decided to fly there in December 2021 to see if he could secure at least partial custody or limited rights to visitation with his children in Russian court.
"Society doesn't consider fathers to be as important as mothers," Carol said. "They don't take into consideration that maybe there are fathers out there that are willing to fight for their children."
Not long after David arrived in Moscow and rented a room near where Koptyaeva was believed to be living, the former spouses ran into each other, according to Carol, who alleges that the ex-wife then contacted Russian authorities to make the same past child abuse allegations that Texas authorities could not substantiate.
David was soon arrested by law enforcement in Moscow.
"After reviewing the decision to initiate a criminal case against me, I think that this is absurd," court records say that David told Russian investigators during an interrogation. "I did not take the actions set forth in the decision to initiate a criminal case against me."
"I'm sure he was panicked," Aaron said. "You feel so helpless."
'It was all made up to destroy him'
David's detention in Russia has come as news to prosecutors in the Lone Star State.
"We were not aware that Mr. Barnes was being held in a Russian detention center," Montgomery County District Attorney's Office Trial Bureau Chief Kelly Blackburn told ABC News when informed of Barnes' incarceration. "At this time, there are no accusations out of Montgomery County that we are aware of that would allow Mr. Barnes to be held in custody."
Nor have any child abuse charges been made against David in neighboring Harris County, which covers the part of Houston also referenced in Russian court documents, according to the district attorney's office there.
A 2014 petition for divorce that was filed on Koptyaeva behalf said that "Petitioner believes that Respondent [David Barnes] has a history or pattern of sexual abuse directed against" one of the children, but did not go into detail.
"There was not a lot of information in 2014," Carol said. "All I remember from talking to David was she started accusing him of some kind of abuse, but there was nothing definitive really said."
In 2017, a settlement agreement between David and Koptyaeva noted in part that Koptyaeva was "to refrain from making statements, either written or oral, to any third party, alleging that ... [David Barnes] ... molested his minor child and/or engaged in improper sexual contact with his minor child" -- though she did not waive any legal reporting duties.
An incident report from a constable's office in Montgomery County said that law enforcement interviewed Koptyaeva and the children in 2018 regarding sexual assault concerns that she reported. A search warrant was subsequently executed on David's apartment in The Woodlands, but no charges were ever filed.
"I know my brother. I know that he loved his children and he would never do those things that she has accused him of," Aaron said. "It was all made up to destroy him and to get the children away from him."
While David is not currently facing criminal charges in Texas, the same cannot be said for Svetlana Barnes, who was indicted in 2019 for interference with child custody, a felony.
The Montgomery County Sheriff's Office alleged that despite a judgment allowing David to have partial custody of the two children, Koptyaeva "failed to comply with any condition for travel outside of the United States with the children," and left the country with the boys on a Turkish Airlines flight from Houston to Istanbul on March 26, 2019.
"Svetlana Barnes still has yet to be arrested on the charge of interference with child custody, and the warrant for her arrest is still active," Blackburn said.
Interpol, the International Criminal Police Organization, considers March 26, 2019, to be the date on which the children disappeared. The organization, which published yellow global police notices containing pictures of the boys, still considers them missing.
In an attempt to reach Koptyaeva for comment, ABC News sent an email to an address previously associated with her, but received an unsigned response from the email account that stated in part, "as her attorney I won't recommend her talking to you."
'I want to see his release'
The news that David is being detained in Russia has prompted calls for his release from many of those closest to him, including his employer.
"We continue to hope for his well-being and safe return home as soon as possible," Philip Ivy, vice president of Houston-based engineering firm KBR, said.
David's arrest was covered by state media outlets in Russia, but has not previously made headlines in the U.S.
In the months since he was taken into custody, Barnes has been visited by representatives of the U.S. Embassy in Moscow, according to emails between his family and the State Department. A trial date has not yet been scheduled and his future remains uncertain.
"We are aware of reports of the arrest of a U.S. citizen in Moscow," a U.S. State Department spokesperson told ABC News. "We take seriously our responsibility to assist U.S. citizens abroad, and are monitoring the situation. We stand ready to provide all appropriate consular services in cases where U.S. citizens are detained abroad."
Back in Huntsville, his family and friends are hoping that he will be able to rejoin them soon.
"I want to see his release," said his sister Aaron. "He is being held there as guilty until they can prove him innocent, but there's nothing to hold him there, there's no evidence of anything, [and] he did not do anything. We would like some action taken for his freedom."
"President Biden, if you could help David in any way, God bless you," said his friend Carter. "We want him back."
ABC News' Patrick Linehan contributed to this report.