A Casper man was sentenced in Natrona Count District Court on Wednesday to 20 to 30 years in prison for first-degree sexual assault of a minor.

Matthew Daniel Henderson, 33, heard the sentence from Judge Kerri Johnson after relatives of the victim spoke for more than a half-hour about what the abuse did to them and the people they know.

Henderson declined to speak to either Johnson or the nearly full courtroom.

In August, Henderson was charged with one count of first-degree sexual abuse of a minor, three counts of second-degree sexual abuse of a minor and two counts of third-degree sexual abuse of a minor. If the case had gone to trial and he was convicted on all counts, he could have faced up to 140 years in prison.

He pleaded not guilty to the charges in September.

In November, he pleaded guilty to the single count of first-degree sexual assault. The other five counts were dismissed.

Friday, Henderson through his attorney Ian Sandefer filed an objection to part of the presentence investigation report, saying he pleaded guilty to the most serious charge in order to spare the victim from reliving the offenses.

The document also said that Henderson was remorseful to the point that he cried numerous times when he made oral and written confessions, and that he had to be put on suicide watch in the jail because of the emotional reaction after the confession.

Court records say a Casper police detective began investigating on July 20 after the victim reported the allegations to her mother, who in turn called the girl's counselor, and the counselor contacted the Wyoming Department of Family Services.

In a forensic interview at the Children's Advocacy Project, the victim said that Henderson had "started doing things he shouldn't be doing."

The victim explained that Henderson had undressed and touched her several times before the abuse became more severe. At one point, the victim told the interviewer, Henderson went to the victim's room, removed his pants and underwear, and then asked her to touch his genitals.

She told investigators that she reported the incident so the same thing would not happen to her younger sister when she grew older.

Wednesday, one of the people familiar with the situation said the abuse led to one child being afraid to sleep with the light off, and another always keeping the door closed at night.

Before the abuse was reported, the victim cut herself six times one day, that person said.

The victim has had trouble in school, has crying fits and resists efforts to touch and comfort her, that Henderson was grooming the younger sister for abuse.

However, that person said the family has become stronger with the help of relatives, law enforcement, the Department of Family Services, counselors and their church.

The victim told Johnson about her struggles in school, her attitude problems and her anxiety, and asked the judge to punish him for the sake of others.

"I hope he does not hurt others the way he hurt me," she said.