DENVER (Reuters) - An elected sheriff from a rural county in Colorado has been arrested on suspicion of sexually assaulting a developmentally disabled woman at his home before transporting her to jail, court documents showed on Wednesday.

Sedgwick County Sheriff Thomas Hanna faces felony charges of sexual assault of an at-risk adult and sexual conduct with an inmate, as well as misdemeanor counts of official misconduct and soliciting prostitution, an arrest warrant affidavit said.

According to the affidavit, Hanna was transporting the woman from the town of Julesburg to a lockup in a neighboring county on Aug. 10 when he took her to his house and asked if she wanted to earn $60.

The woman, who investigators described as functionally “delayed,” said Hanna told her, “I just want sex,” then ordered her to strip before groping her and threatening to lock her up for the rest of her life if she reported the incident.

Hanna, 43, who was elected in 2014, was taken into custody on Tuesday after a criminal probe conducted by Colorado Bureau of Investigation agents and district attorney investigators, court records showed.

Hanna made his first court appearance on Wednesday, where his bond was set at $250,000, and he will be charged at a later date, according to a statement from a Denver-area district attorney who was appointed special prosecutor in the case.

Hanna could face a sentence of eight years to life in prison if convicted of the most serious charge, the prosecutor said.

The investigation of Hanna was launched after one of his deputies, Larry Neugebauer, told authorities he saw the sheriff put the prisoner in his personal truck, a violation of department policy, and later saw the truck and a patrol car parked outside Hanna’s home.

Hanna denied to investigators that he assaulted the woman, but admitted it was a “poor decision” to take her to his house to discuss criminal activity in the area, the affidavit said. He declined to take a polygraph test.

Investigator Jeff Huston said the woman, who has not been identified publicly, was timid, hard to understand and had difficulty putting her thoughts together when she was interviewed by police.

The woman told Huston she was “ashamed” of her disability and did not understand that she had been victimized, the affidavit said.

Sedgwick County is a sprawling but sparsely populated farming and ranching area in the northeastern corner of the state bordering Nebraska.