IOWA CITY, Iowa (AP) — An Iowa Department of Transportation driving instructor forced a customer to view sexually explicit photos and videos of himself during an exam and then threatened her to keep quiet, authorities said Wednesday.

John Wayne Alexander of Ankeny is charged with felonious misconduct in office and harassment based on his alleged actions during the Feb. 26 driving test. The 60-year-old abruptly retired from the DOT in March amid a disciplinary investigation.

Alexander worked as a senior driver's license clerk at the DOT's driver's license station in Ankeny, which serves customers in the state's largest metropolitan area. He's pleaded not guilty and disputed the allegations.

"Really it's no big deal. Nothing happened. That's all I can say," he said Wednesday.

A 47-year-old woman seeking to have her license reinstated told police that Alexander instructed her to pull into the parking lot of a Mills Fleet Farm store shortly after the test began, saying he wanted to smoke a cigarette.

An agitated Alexander then gave his phone to the woman and said that he needed her to delete several photos, which showed him "in various forms of self-pleasure and undress," a complaint said. Fearing for her safety and license status, the woman says she deleted the images as told. She gave the phone back to Alexander, who then forced her to watch a video of himself masturbating and using a sex toy, police said.

After 20 minutes, Alexander instructed the woman to drive back to the DOT office. He told her that she had passed the exam "but if she were to tell anyone, (Alexander) would lose his job and he would know who told." After obtaining her license, the woman reported the incident to Ankeny police.

The department removed Alexander from contact with the public and was concluding an investigation when Alexander retired March 23, motor vehicle division director Mark Lowe said. The agency hasn't received other complaints about Alexander, who worked at the station for three years and in other state jobs dating to 1993.

"We were shocked and surprised by the charges," Lowe said. "It's not the type of behavior we want either from a customer safety standpoint or an integrity standpoint."

Lowe said DOT isn't aware of similar charges ever being filed against one of its driving evaluators, who conduct tens of thousands of exams every year. He said customers should feel safe taking tests, noting that employees go through background checks and that DOT uses software to monitor drives. He said that technology was helpful in investigating Alexander and would be upgraded to send alerts when cars aren't moving for some time.

The woman's account is supported by surveillance video showing her car parked for 20 minutes in the lot. A download of Alexander's phone also yielded the explicit content she described, police said.

The felony misconduct charge is based on the allegation that Alexander didn't give the woman a legitimate exam yet gave her a false passing grade. The harassment charge is a misdemeanor but prosecutors have requested that Alexander be placed on the sex offender registry if convicted due to the sexual nature.

In a hearing last week in which he sought unemployment benefits, Alexander testified that he told the woman to stop in the lot after she became sweaty and shaky. He said he told her to drive back to the DOT office after she smoked a cigarette and took some pills, adding that he was able to evaluate her skills despite the short drive.

Administrative Law Judge Nicole Merrill cast doubt on Alexander's credibility and concluded the evidence of misconduct was strong. She denied benefits, saying Alexander's actions went "against commonly known acceptable standards of work behavior."

Alexander, whose salary was $48,000, would be eligible to collect retirement benefits under Iowa law, which doesn't strip them when employees are accused or convicted of misconduct.