William Butler, a Nevada County, Calif., Sheriff's Office sergeant who was accused of inappropriate sexual conduct with a prisoner he was transporting through Nye County, may soon be facing charges from the Nye County District Attorney's office.

Butler was caught with Jeremy Mattson, 23, in a Tonopah hotel room last October.

Mattson was being transported by Butler from the detention center in Pahrump to the Wayne Brown Correctional Facility in Nevada City, Calif.

Nye County District Attorney Robert Beckett said that evidence taken from the hotel room in which Butler and Mattson were found has been processed and the results are currently being reviewed by John Friele, Tonopah assistant district attorney.

A Nye County Sheriff's Office (NCSO) detective is also investigating the incident.

Mattson told The Union, a Nevada City newspaper, that Nevada County officials agreed to settle with him and gave him $10,000 to sign a document stating he would not sue Nevada County as part of the settlement.

Beckett said Mattson's civil settlement would have no effect on the Nye County D.A.'s office decision of whether or not to file charges against Butler.

Because the alleged crime occurred in Nye County, it has legal jurisdiction.

Mattson and Butler were found in the Tonopah hotel room by NCSO deputies at 3 a.m., Nov. 1, after Mattson called 911.

Butler reportedly made several unwanted sexual advances to the inmate throughout the course of the night.

According to Mattson, the sergeant removed his handcuffs and allowed him to pump gas during their drive.

Butler then offered Matson the option of staying in a hotel room instead spending the night at the Tonopah jail.

Mattson reportedly said the offer to stay in the hotel also included a reminder from the sergeant that he could shoot Mattson if he attempted to escape.

At the hotel, Mattson said the officer first attempted to jump into the shower with him.

Mattson got out of the shower and went to bed, but the sergeant allegedly got into bed with him.

The inmate said that Butler told him to masturbate, and he did what the officer asked because he remembered the previous shooting comment.

After he heard the officer snoring, Mattson said he called 911.

Butler, who was retired but contracted by the county to transport Mattson, had worked for the sheriff's office for nearly 30 years.

Mattson reportedly took the $10,000 offered to him by county officials and spent it within two weeks of receiving it.

He said he spent the money paying a few months' rent on his Pahrump apartment and on his three children and girlfriend.

The inmate, who was facing assault charges from a fight that allegedly occurred at the Wayne Brown Correctional Facility, said he accepted the settlement because he wanted to get out of jail.