Inside the harrowing case of 14-year-old ‘runaway’ Chyenne Kircher whose decomposing body was found strangled to death – only for her sexually abusive STEPFATHER to be unmasked as her MURDERER

A popular crime documentary is set to reveal the harrowing true story of a 14-year-old schoolgirl who was sexually assaulted and strangled to death by her own stepfather.

Chyenne Kircher disappeared from her family home in East Dubuque, Illinois, in October 2011, with a note left by the teen claiming she had run away.

Widespread searches were launched, but the situation took a shocking turn two years later when her decomposing body was found buried in the woods just 100 meters from the house.

His father-in-law Terry Abbas, now 50, will ultimately be found guilty of murder, sexual abuse and covering up a homicide.

Here, FEMAIL revealed the chilling details as an upcoming episode of FBI True explores the disappearance of Chyenne Kircher.

Chyenne Kircher, of East Dubuque, Illinois, was sexually assaulted and strangled to death by her stepfather Terry Abbas

Chyenne had grown up in a dysfunctional household where she lived with her mother, stepfather, and two brothers, as well as another man who she told teachers was her mother’s boyfriend.

Amy Taylor, who was head of special education at the girls’ school, said: “She always seemed a bit disheveled.”

“She needed tender care. She was a student who liked attention – maybe not always positive attention.

“She struggled with certain social settings, but she really wanted to belong there. She needed to belong.

Social services were called to the family several times, but things took a dramatic turn in October 2011 after Chyenne failed to show up for school.

Her family went looking for her and contacted her friends, but eventually reported her missing to the local police department.

They claimed she fled after finding a handwritten note left in a car that said “don’t come get me.”

Chyenne had grown up in a dysfunctional household where she lived with her mother, stepfather, and two brothers, as well as another man who she told teachers was her mother’s boyfriend.

The situation took a shocking turn two years later after his decomposing body was found buried in the woods just 100 meters from the house.

Abbas took police to the grave site but later revealed that he had actually dug the grave the day before in an act of premeditation

Nonetheless, police launched a massive search involving more than three different forces.

Agents also reviewed Chyenne’s internet history and discovered that she had spoken online with older men across the United States – from Florida to Texas and Alaska.

But further investigation revealed that none of these people were involved in her disappearance.

Family and friends continued to keep watch, but with no immediate signs of foul play, authorities had little to do and the trail became uncertain.

But when a new task force was set up almost two years later, officers decided to intensify the search for Chyenne again.

During the investigation, suspicion fell on stepfather Terry Abbas, with Chyenne having previously told friends that he had sexually assaulted her.

She also told one of her teachers that she had caught him watching porn and threatened to tell her mother.

As authorities framed Abbas as a “threat” to Chyenne, they conducted a polygraph test that revealed he had lied.

He was immediately taken to a separate interrogation room where his story began to unfold to the point where he confessed.

‘Well… you have your man. You have Terry Abbas. Chyenne is not with us. She’s gone,” he said in an interview.

Abbas also said he also coerced the 14-year-old into writing that note about a month earlier as part of a “practical joke” the two men were going to play on Chyenne’s mother.

In his first confession, Abbas told police he took the youth into the woods behind the family home to run around.

He claimed he slipped and passed out – adding that when he woke up, Chyenne was dead and his hand was around her neck.

“Before I knew it, I was standing over his body,” Abbas said before breaking down in tears.

‘My life is over. It’s been over for a long time, I just haven’t faced reality.

He then revealed he had sex with Chyenne in the garden of the family home before strangling her to death.

“The last thing I remember was my hand was on her neck, for some reason… She was squeezing it, I guess. Then I panicked.

Abbas claimed he then dug a hole about five feet deep and dumped her body less than 100 meters from the family home.

He took the police to the grave site, but he did so later. reveal that he had actually dug the grave the day before in an act of premeditation.

Abbas also said he had also forced the 14-year-old to write this note about a month earlier as part of a “p”racist joke that the two men were going to play on Chyenne’s mother.

He pleaded guilty to six charges in October 2013, including three counts of murder, two counts of aggravated criminal sexual abuse and one count of concealing a homicide death.

The killer was sentenced to life in prison without the possibility of parole.