Inside the Bizarre Tale of Natalia Grace, Adopted from Ukraine: Is She a Child or an Adult 'Sociopath?'

Natalia Grace, an orphan from the Ukraine, was adopted in 2010 by an Indiana couple.

Michael and Kristine Barnett believed they were adopting a 6-year-old girl. But soon, they became suspicious of her age, leading to a bombshell claim: that Natalia, who has a form of dwarfism called spondyloepiphyseal, was merely posing as a child — and was really an adult woman with sinister intentions.

The strange case is the subject of a new docuseries, The Curious Case of Natalia Grace, debuting across three consecutive nights on ID beginning Monday, May 29, airing nightly from 9-11 p.m. ET/PT. (A trailer for the show is below.)

The docuseries features exclusive interviews with the Barnetts as well as members of Natalia's adoptive family, as well as never-before-seen footage.

The Barnetts claimed Natalia tried to harm them and their biological children. Natalia was accused of trying to poison Kristine's coffee and kill her by dragging her towards an electric fence. Natalia was also accused of placing clear thumb tacks on the stairs face up so that they would step on them.

Michael Barnett told Good Morning America that doctors allegedly treating Natalia told them "this person is a sociopath. This person is a con artist. You are all in danger."

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

In 2012, two years after Natalia was adopted by the Barnetts, the couple petitioned Marion County Probate Court to have her age legally changed to 22, changing her birth year from 2003 to 1989.

The following year, the couple moved with their three sons to Canada without her, leaving her alone in an apartment in Lafayette.

The Barnetts, who later divorced, were charged with neglect of a dependent. Prosecutors couldn't charge the couple with neglect of a child because of Natalie's court-ordered age change.

Natalia testified during Michael's trial saying that she didn't want to live in Lafayette.

"I wanted to be with the Barnetts," she said, the Lafayette Journal & Courier reported. "I wanted to live with them."

Michael was found not guilty of three counts of neglect and conspiracy to commit neglect of a dependent in 2022, the Associated Press reported.

In March, charges against Kristina were dropped, according to WTHR.

The Curious Case of Natalia Grace airs across three consecutive nights on ID beginning Monday, May 29, airing nightly from 9-11 p.m. ET/PT.