MACHIAS, Maine — A 52-year-old Calais man on trial for eight sex crimes against three young girls testified in his own defense Wednesday, categorically denying the claims by all three.

Clifford Thornton II disputed the accusations of prosecution witnesses who testified earlier in the Washington County Superior Court trial that began Monday.

Thornton, employed as a mechanic for the Woodland Pulp mill in Baileyville, is on trial for one count of gross sexual assault and seven counts of unlawful sexual contact. The alleged offenses, which purportedly took place in Thornton’s home or on his property, date back to the mid-1990s, with the most recent offense in 2008; the victims were under age 12 or 14 at the time.

Wearing a black jacket over a light, untucked shirt and black slacks, he testified calmly Wednesday as he rebutted the allegations made by the three, who are now 16, 20 and 25 years old.

Bangor defense attorney Stephen Smith referred Thornton to the testimony of each of his accusers and asked him about their statements one by one.

Asked if he had forced the 16-year-old to perform oral sex on him when she was 10, Thornton replied, “No, I did not.” He also refuted her testimony that he had touched her sexually and shown her a nude photo of another victim on a computer in his bedroom.

He similarly denied he groped the second victim through her clothing while giving her a ride on a snowmobile.

When asked if he had ever taken nude photographs of the third victim or touched her sexually, Thornton again answered, “No, I did not.”

Thornton also refuted the testimony of other witnesses who said he had taken the 16-year-old into his bedroom to help her play a computer or electronic game during a family get-together at his home. The alleged victim testified that he forced her to perform oral sex on him after they were alone in the bedroom during that family gathering.

“I did not take her into the bedroom,” Thornton testified.

So other witnesses who described hearing and seeing him accompany the girl to his bedroom were wrong, suggested First Assistant District Attorney Paul Cavanaugh during cross examination.

“Exactly,” answered Thornton.

The defendant’s testimony was bolstered by a series of defense witnesses who began testifying on his behalf Tuesday and continued Wednesday. Generally, the defense witnesses, including relatives of Thornton and family members, said they never observed any inappropriate behavior by Thornton. Additionally, they testified they never noticed anything unusual with regard to his relationships or contacts with his three accusers.

Thornton’s testimony capped and concluded Smith’s defense of his client. Attorneys for both sides were scheduled to make their closing arguments to the jury of six men and six women on Thursday morning, and the jury was expected to begin deliberations afterward.

The charge of gross sexual assault pertains to the 16-year-old. Six counts of unlawful sexual contact — any touching of the genitals, even when the victim is clothed — pertained to a second victim, and one count to a third.

The jury traveled by bus to Calais on Monday to visit the Thornton home and property where the crimes allegedly occurred. Attorneys for both sides and Justice E. Allen Hunter also traveled to Calais to accompany the jury.

Thornton was arrested in August 2011 and has remained free on bond.