With their six children grown and out of the house, the timing seemed right for the Indiana couple to adopt a child. Financially and emotionally, they were ready to share their home.

In 2014, the couple adopted a young child from China through Bethany Christian Services. The experience was “positive,” so they decided to adopt again, about a year later, through a different agency, according to Indianapolis attorney Jonathan Little.

But the next child they adopted, Little says, wreaked inconceivable damage in the couple’s Terre Haute home.

Identified in court documents only as “L," the adopted child who the couple believed to be 12 had endured horrific sexual abuse in China — and then inflicted that abuse onto other children in their home, the couple says.

Now, they’re suing the adoption agency — Chinese Children Adoption International — for allegedly failing to disclose the boy's traumatic past. Little says they also want him sent back to China to keep him from harming anyone else.

The federal lawsuit, filed Aug. 13 in U.S. District Court in Colorado, accuses the agency that’s based there of fraud and negligence. Little told IndyStar that the adoption agency failed to inspect the conditions of the China orphanage that L came from.

Instead of vetting its orphanages, the agency was more focused on making L and other kids as appealing as possible, to get them adopted quickly in the U.S., he alleges.

“They appear to be a credible organization,” Little said. “But in reality, they’re not doing their due diligence about where they’re adopting these kids from.”

A spokesman for Chinese Children Adoption International told IndyStar the agency can't comment on pending litigation.

Suit: Teen assaulted other children

After adopting their first child, N, the couple welcomed L into their household in September 2015, the suit said. Within a month, N began showing symptoms of a problem: his hair was falling out, he stopped eating and he had a bloody stool. At age 5, the child went bald, according to the lawsuit. Every night he would run into the couple’s room to get into bed with them.

In 2016, the couple adopted a third child, J. After he entered their home, he would wake up “screaming and crying,” the lawsuit said. He began complaining of pain in his buttocks. The couple thought the pain came from cigarette burn wounds he’d suffered in a Chinese orphanage.

But then, they say, they learned the truth.

When confronted by the couple, L admitted to raping his brothers, according to the lawsuit. He would set his alarm at 3 a.m., and every night he'd wake up at that time and sexually assault the boys, the couple said.

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The couple took L to a behavioral center in March 2016. They learned that he had been raped and prostituted at the orphanage he was adopted from in China, the lawsuit said.

The boy reportedly told a therapist that he still had “strong sexual urges” and would abuse the boys again if given the chance.

The lawsuit contendsthat the adoption agency either knew about the boy’s past and neglected to tell the couple — or they didn’t take the time to find out about it. Either way, the abuse left lasting effects on the family, who left their home and their business to escape the traumatic memories, according to Little.

“(L) would not have been allowed to emigrate to the U.S., nor would the Martins have adopted him if they’d known he was a rapist,” Little said.

The lawsuit also accuses Chinese Children Adoption International of lying about the boy’s age. The agency allegedly said he was 12, when he was actually 15 or 16, the couple said.

Children left scarred

It wasn’t just L's past that revealed itself after the adoption process was finalized, the suit said. J — their third adopted child — was diagnosed with hydrocephalus, which is a brain-related condition, as well as cerebral palsy, according to the lawsuit.

The couple was aware of J’s condition and was interested in caring for a child with special needs, but they say they weren’t told about a brain tumor the child received surgery for in Hong Kong.

They found out about the surgery, Little says, when the hospital invited them to a gala it was having to celebrate the success of the operation.

The family incurred “unexpected health costs” related to J’s condition, the lawsuit said. The adoptions alone cost the couple more than $100,000, according to Little.

Then there's the hundreds the couple spends each week on therapy, Little said. Since the abuse, both J and N suffer from post-traumatic stress disorder and attachment disorder. N is depressed, has anxiety and panic attacks and is afraid of sleeping alone. J has nightmares and aggression, according to the lawsuit.

“These kids are not doing well,” Little said. “They're scared in school. You already have kids who were abandoned by their birth parents. And now (they’re) confused by their sexual feelings. They are terrified of being raped. They're scared of their own shadows.”

Lengthy adoption process

A spokesman for Chinese Children Adoption International declined to explain the agency's adoption process to IndyStar, but an expert indicates it likely wasn’t easy or quick for the Martins to adopt three children internationally.

“It is a very thorough process,” said Inna Pecar, the director of Kids First Adoption. "It can (take) a year to four or five years.”

Parents seeking to adopt overseas must be home-study approved, Pecar said. Home study is an evaluation conducted by a licensed caseworker that determines whether the parents are fit to adopt a child, according to U.S. Citizenship and Immigration Services.

The process is long and expensive, Pecar said. Prospective parents are expected to provide financial and medical information, undergo educational training and give references.

If the parents receive home study approval, they then have to wait for approval from immigration services. Once they receive that, the adoption agency works with coordinators overseas to move forward with the adoption.

It's on the agency, Pecar said, to give parents as much information about the child as they can provide. That could be whether the child was abandoned at a young age, or has a medical condition.

"It’s the job of home study to require educational study," she said. "The placing agency is responsible (for providing) accurate information," and explaining what that information means, Pecar said.

Parents want to send teen back

The lawsuit says that L is in state custody for the assaults. In March 2016, he was charged with two counts of sexual battery and sent to the Vigo County Juvenile Detention Center, according to the suit.

Little says L remains in Vigo County custody but is currently at a treatment facility in Marion County. The Vigo County Sheriff's Office declined to confirm this detail to IndyStar. The office says it doesn't release information on juveniles.

According to Little, when the teen turns 19, he will be released into the general population in Indiana. Little says the couple has been working with Indiana, the State Department and the Hague Convention to return him to China. The State Department declined to comment to IndyStar, citing "privacy considerations."

Little says his clients sympathize with what the teen suffered in China.

“My clients feel awful,” he said. “What was (L’s) life over there? What are they sending him back to?"

But the couple continues to care for and protect their two children.

“They have liquidated their assets, their retirements, everything," he said. "They are caring for those boys. Those boys are nice, sweet kids. It’s a sad situation.”

Contact IndyStar reporter Crystal Hill at 317-444-6094 or cnhill@gannett.com. Follow her on Twitter: @crysnhill.