SCOTTSDALE, Ariz. - Scottsdale police arrested Salt River Police Officer Jay Hun Wu Thursday for unlawful sexual conduct with a woman in his custody.

The woman, 43, had contact with Wu, 45, as the subject of a criminal investigation, according to Scottsdale police.

On March 29, Wu gave the woman a courtesy ride to her home.

Reportedly, she was in the back of the car, uncuffed and she asked officer Wu to let her out at her residence but, police say, he pulled over in the 9100 block of North Cerrito Vista, next to a residential wall.

WATCH: Victim speaks at suspect's first court appearance

According to Scottsdale police, he opened the back of the vehicle and said he needed to pat the woman down before he sexually abused her under her clothing.

He then gave her his business card and told her to call if she ever needed anything.

The victim immediately told her family and Scottsdale police about the encounter.

Salt River police coordinated with Scottsdale police on the arrest.

The woman was at Wu's initial court appearance Friday, and shared how the incident has impacted her while Wu stood silently.

"It just really shook me and scared me and I didn't know who to turn to," she said. "But I never want to be touched by someone if I didn't ask them to touch me."

She recalls "nightmares and a lot of crying," saying the incident has "really impacted me emotionally ... to have trust in a law officer an then feel violated."

The officer "misused his power," Sgt. Ben Hoster of the Scottsdale Police Department said, adding, "when police find a bad apple among their ranks, they're quick to remove them."

Officer Wu is now facing a number of charges including sexual abuse, kidnapping and tampering with evidence.

12 News reached out to the Salt River Police Department, but they had no comment. They're referring all questions to Scottsdale police.