HILO >> A former Hilo driver was sentenced to 20 years in prison after pleading no contest to allegations that he sexually assaulted a disabled woman.

Louis Sardis, 65, was a driver for the nonprofit organization The Arc of Hilo, which works with individuals who have developmental or other disabilities.

Two witnesses told police that they saw Louis Sardis assaulting the woman last year in the van owned by the nonprofit.

Deputy Prosecutor Kimberly Angay said Sardis initially confessed to the attack but has since changed his story.

Sardis was sentenced Wednesday after pleading no contest in October to two counts of first-degree sexual assault, the Hawaii Tribune-Herald reported .

The woman’s sister told the judge that Sardis’ actions impacted their family.

“My mom and dad and I . have trouble sleeping at night. My mom has basically gone into a state of depression,” the victim’s sister said. “I feel the sentence the defendant is getting is, basically, letting him off easy, as opposed to what my family is going through.”

Sardis, who is originally from Chuuk in the Federated States of Micronesia, apologized in court.

The victim’s parents filed suit in September against Sardis and The Arc of Hilo, seeking unspecified monetary damages and changes made in the way the nonprofit organization transports and supervises clients.

The Arc of Hilo filed a motion in November seeking dismissal of the civil complaint.